Method for producing a color image and imaging device employing same

ABSTRACT

A method of producing a color image comprising providing input image data from an image source such as a camera; generating an at least three-dimensional look-up table of values of input colors and output colors, wherein the values in the lookup table convert the input image color data to output image color data in an image rendering unit; loading the at least three-dimensional look-up table into an image color rendering controller; loading the input image data into the imaging color rendering controller; processing the input image data through the at least three-dimensional look-up table to produce output color values stored at the addresses in the at least three-dimensional look-up table; and outputting the output color values to the image rendering unit to produce an output image that is perceived to have at least one of enhanced brightness, enhanced contrast, or enhanced colorfulness compared to the input image.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority to U.S. provisional patent applicationSer. No. 61/238,706, filed Sep. 1, 2009, the disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Processing and projection or display of color images on surfaces, ontelevisions, on game displays, on computers or by other electronicdisplay media.

2. Description of Related Art

The projection and/or display of color images is an active area ofcommercial research and development. New image display, television,games, computers and projection products and viewing experiences arebeing launched in the marketplace on a regular basis. In one aspect ofthe marketplace, digital cinema or video projector technology thatutilizes colored light emitting diodes (LEDs) as the source of theprimary colors for imaging, offers the promise of extreme, wide colorgamut along with very long life, low heat illumination. LED brightnessis currently limited, however, requiring three optical systems and threeimage modulators, i.e., one for each of the red, green, and blue (RGB)color channels, for the brightest images. Current projector lamptechnology is of higher brightness and can take advantage of singleoptical systems and single image modulators using complex color filterwheels to provide full color display. In a second aspect of themarketplace, televisions, game displays and computer displays such asliquid crystal displays (LCDs) are now being introduced with LEDs as thebacklit light source to again take advantage of the extreme, wide colorgamut, long life and low heat output of LEDs. In a third aspect of themarketplace, projectors, televisions, game displays and computerdisplays are being introduced with more than the typical three (RGB)colors to improve brightness and expand the color gamut. Such productsoffer the promise and technical challenge of how to best use the widecolor gamut.

In a color image projector, in order to gain the advantage of theavailable wide color gamut, longer life, and lower heat of LEDillumination, and to achieve maximum brightness with a single opticalsystem and single image modulator, the multiple RGB channels may becombined for some portion of time during image frames. Adding thesemultiple RGB channels during an image frame duty cycle will increase thebrightness, but will also reduce the colorfulness by desaturating thepure RGB colors.

Furthermore, in prior art projectors, color rendering is accomplished byprocessing each of the RGB channels independently with matrix operatorsor with one-dimensional color look-up tables. In some projectors, theRGB colors and the combinations of two and three colors may beindependently controlled. However, such control does not provide fullthree-dimensional color processing. With these limited processingoptions, it is not possible to display images optimally in human visualsystem (HVS) perceptual terms. For example, it is not possible to rendervisual lightness contrast without affecting either or both of hue andchroma. Achieving optimal visual processing that provides the brightest,most colorful images, while preserving perceived color accuracy requiresthree-dimensional color processing.

In providing any color image for viewing by a human observer, whether itis an image printed on a substrate, an electronic display, television,or a projection onto a viewing surface, the perception of color stimuliby the human observer is dependent upon a number of factors. In theInternational Lighting Vocabulary published in 1987 by the CommissionInternationale de l'éclairage (CIE), it is noted as follows: “Perceivedcolor depends upon the spectral distribution of the color stimulus, onthe size, shape, structure, and surround of the stimulus area, on thestate of adaptation of the observer's visual system, and on theobserver's experience of the prevailing and similar situations ofobservations.”

Moreover, in a treatise on the stained glassed windows at the cathedralat Chartres, The Radiance of Chartres: Studies in the Early StainedGlass of the Cathedral, (Columbia University Studies in Art History andArchaeology, No. 4), Random House, 1^(st) Ed., 1965, author James RosserJohnson wrote that, “ . . . the experience of seeing these windows . . .is a very complicated experience . . . that spans many aspects ofperception.” Yet fundamentally, “ . . . when the spectator enters theCathedral from the bright sunlight, . . . the visitor must step withcaution until his eyes have made a partial dark adaptation . . . thenthe details of the interior will seem lighter and clearer while, at thesame time, the [stained-glass] windows become richer and more intense.”

Adaptation plays a powerful role in the instance depicted in Johnson'snarrative. By adapting to the darkness or lower, perceived diffuse whiteof the cathedral's interior, the colors of the windows appearexceedingly brilliant, invoking a perception, in the words of VincentScully, Architecture, The Natural and Manmade, St. Martin's Press, 1991,that, “ . . . transcend[s] the statics of the building masses, therealities of this world . . . [creating] a world of illusion, shaped byand for the heavenly light of the enormous stained glass windows.” Whilesuch a perceptual experience is certainly complex and affected by themany characteristics of the human visual system (HVS), the richness ofit is largely and simply made possible by the broad extent ofsensitivity of the HVS and its innate ability to adapt to its surround.

The HVS is capable of adapting to an incredible range of luminance. Forexample, the HVS may adapt its light sensitivity over a range of abouteight orders of magnitude, e.g., from a starlit, moonlit night having aluminance of about 0.0001 candela per square meter (cd/m²) to a brightlylit summer day of about 600 to 10,000 cd/m². Equally remarkable is thatthe HVS may accommodate over five orders of magnitude of luminance atany given instant for the perception of complex visual fields that areroutinely experienced. This adaptation occurs relative to diffuse white,i.e., an area in the scene that appears white. The perceptions oflightness and chroma are then relative to this white. The higher thebrightness of the perceived white, the lower the brightness and chromaof similarly illuminated objects in the scene will appear to theobserver; conversely, the lower its brightness, the brighter and morecolorful such objects appear.

This means that changing the stimulus that appears white affects theappearance of all other stimuli in the scene. For a display orprojection of an image, these powers of adaptation can be harnessed toexpand the gamut of the medium in the perceptual sense. For any imagedisplay, and particularly single modulation LED displays such as thoseemploying a digital micromirror device (DMD), the projected image can bemade to appear brighter by the addition of light from combining RGBcolors for some portion of the image frame time. In so doing, the powersof HVS adaptation are exploited to increase the apparent brightness andlightness contrast of the displayed images. For displays illuminated byred, green, and blue LEDs, although the added light reduces the actualdisplay color gamut provided by the “LED primaries,” the R, G, and Bprimary colors of the LEDs often exceed the current video standards,such as e.g., ITU Radiocommunication Sector (ITU-R) RecommendationBT.709, which is the United States standard for the format ofhigh-definition television and consumer digital media. Thus some colorswhich are possible to output by the R, G, and B LEDs, or displays withmore than three colors and extended color gamut are not available to beencoded in the input color data for display in accordance with suchstandards. Optimal use of these extended colors requires fullthree-dimensional color processing and can be further optimized usingknowledge of the HVS. Prior attempts to process the current videostandards, such as with one-dimensional color processing and colormatrices, or without use of HVS models have resulted in unsatisfactoryand unrealistic displayed images and high rates of product return byconsumers.

Illustrative of some of these attempts, FIGS. 1A-1D are two-dimensionalschematic diagrams of various prior art ways for processing input colordata to produce output color data for rendering a color image. FIG. 1Ashows a color hue/saturation/contrast/brightness method, depicting theglobal controls that rotate hue, stretch saturation and contrast andraise brightness. All colors are changed with these controls with no wayto isolate a given color or color region like flesh tones.R_(in)/G_(in)/W_(in) are input HD709 standard colors, andR_(out)/G_(out)/W_(out) are more pure output LED Colors. There are fourcontrols, and if each control is provided with 20 settings for example,there are 80 global choices.

FIG. 1B shows a color matrix method depicting a linear matrix globalcontrol that rotates and scales the color axes. All colors are changedglobally with no way to isolate local colors like flesh tones.R_(in)/G_(in)/W_(in) are input HD709 standard colors, andR_(out)/G_(out)/W_(out) are more pure output LED colors. If a 3×3 matrixis used, there are nine global choices.

FIG. 1C shows a color gamma tables method depicting gamma globalcontrols that independently maps each input color non-linearly to dothings such as increase contrast. It can be seen that, e.g., red changesare the same for all green values. The same relationships occur withother combinations of primary colors. Thus gamma controls are global,with no way to locally isolate colors, such as flesh tones.R_(in)/G_(in)/W_(in) are input HD709 standard colors, andR_(out)/G_(out)/W_(out) are more pure output LED colors. With threeprimary colors having 4096 settings, there are 12288 global choices.

FIG. 1D shows a 2D example of an RGBCYMW seven color mapping method. Inthis simple example of 7-color tetrahedral processing, the RBG/RGWtriangles are independently processed using linear interpolation ofinput/output control values at each vertices. This is a global control,with no way to isolate local colors or regions like flesh tones.R_(in)/G_(in)/W_(in) are input HD709 standard colors, andR_(out)/G_(out)/W_(out) are more pure output LED colors. With 14 In/Outcolors, there are 14 global choices. R_(in)/G_(in)/W_(in) are inputHD709 standard colors, and R_(out)/G_(out)/W_(out) are more pure outputLED Colors.

Digital Cinema Initiatives, LLC (DCI) is a joint venture of major motionpicture studios, which was formed in 2002 to create standards fordigital cinema systems, including image capture and projection. Thedigital color standard adopted by the studios for professional moviereleases in the DCI format is 12 bits per primary color, nonlinear CIEXYZ Tristimulus values. This is the first time that a digital standardhas been established that is encoded in visual color space and thereforeindependent of any imaging device. For example, using this standard, thesame digital file can be displayed to produce the specified color on atelevision or a printer. The color gamut of this digital color standardis larger than any possible display.

FIG. 3 is a diagram of color gamuts, including color gamuts of the DCIand HD709 standards, and color gamuts of various media and/or imagingdevices. It can be seen that in diagram 400, the color gamuts 406, 408,410, and 412 of the various imaging devices are substantially largerthan the HD709 standard 404. Accordingly, to take full advantage of thecolor capabilities of these imaging devices 406-412, the color gamut ofthe HD709 standard must be mapped upwardly, to render the full colors ofthe larger color gamut, while simultaneously preserving flesh tones andother memory colors, and optimizing the particular device for viewing ina particular environment.

It can also be seen that the large triangular boundary 402 thatrepresents the DCI standard encompasses all of the color gamuts of themedia and/or imaging devices, as well as the color gamut of the HD709standard 404. Accordingly, the digital color standard input color gamut402 must be contracted or reduced to fit within the color gamut of aphysical display such as a television or projector. Truncating orclipping those input digital color values of the DCI standard that lieoutside of the color gamut boundary of the display device will causeloss of color saturation and detail and create a visually sub-optimaldisplayed image. Conventional video processing using one-dimensionalcolor tables and linear matrices will also produce sub-optimal displayedimages. Optimal display of these contracted colors requires fullthree-dimensional color processing and can be further optimized usingknowledge of the HVS and the state of visual adaptation in particularviewing environments.

Also, image and video media display products are now being reduced insize. Examples of such products are the new miniature pico-projectorsand portable, handheld displays such as iPods® or iPads®. Because ofpower, heat, and size limitations, these displays generally have reducedcolor gamuts due to reduced contrast or reduced color saturation. Theyalso are often used in widely differing viewing environments bothindoors and outdoors. Improvement of the overall quality of thesesmaller gamut displays with conventional image and video input iscritical to product value. Conventional video processing usingone-dimensional color tables and linear matrices will also producesub-optimal displayed images. Optimal display of these contracted colorsrequires full three-dimensional color processing and can be furtheroptimized using knowledge of the HVS and the state of visual adaptationin particular viewing environments.

Additionally, the capabilities of HVS adaptation are affected by theviewing environment. In a dark room, higher contrast is needed in aprojected or displayed image for an equally perceived viewing experienceas compared to a room with normal room lighting or viewing the sameimage in bright outdoor lighting. Relative to bright outdoor lighting,the HVS adaptation to the dark room and the lower overall imagebrightness combine to reduce the perceived image contrast. In a brightlylit room, less contrast is needed due to brightness adaptation and morecontrast is needed due to viewing flare from room lights illuminatingthe dark areas of the displayed image.

In image displays, televisions, and/or projectors using high brightnesslight sources or expanded or reduced color gamuts, there is therefore aneed in displaying and/or projecting images to optimize the increase inperceived brightness, contrast, and colorfulness while preservingexpected memory colors of the displayed image such as flesh tones. Suchan optimization should take into account that not all colors should beadjusted in the same manner and to the same extent. To do so wouldresult in images containing certain details that appear unsatisfactoryto a human observer. For example, if a flesh tone of a face in an imageis modified in the same manner as a relatively saturated color ofanother object in the image, the face will be perceived as “pink,”“orange,” or “burnt” by an observer and thus will be perceived asunsatisfactory. There is therefore a need to achieve this optimizationwhile also preserving certain known colors, such as flesh tones, greytones, named colors (such as commercial “brand” colors), and other“memory” colors in the image. Prior attempts to process the video inputswith one-dimensional color processing and color matrices for suchextended brightness, contrast or color gamut displays, have resulted inunsatisfactory and unrealistic displayed images and high rates ofproduct return by consumers

Current projectors, televisions or displays that attempt to enhance orimprove perceived color quality with processing that is in any waydifferent than exact colorimetric color reproduction, do not preservememory colors in the background. A memory color may be characterized asa localized volume in a color space, as will be described subsequentlyherein. The algorithms used in current image displays, televisions andprojectors cannot uniquely preserve a volume within a three-dimensionalcolor space while changing a different volume within the samethree-dimensional color space using one dimensional tables, or matrices,or enhancements which are applied to all colors in the 3D space. Forexample, in some image projectors, color enhancement is attempted usingoutput color definitions of the seven input colors RGBCMYW(red-green-blue-cyan-magenta-yellow-white). This may allow one toprovide a bright white in an image without changing red, for example,but it does not allow one to specify any point or localized volume of amemory color in a 3D color space, which is required to preserve thatmemory color. As a result, when current image displays, televisions andprojectors provide enhanced colors, they do so across the entire colorgamut, “enhancing” certain memory colors such as flesh tones such that atypical human observer finds them unsatisfactory and not perceptuallyoptimal. In such image devices, the color enhancement is somewhatarbitrary; it does not preserve memory colors, nor produce a perceiveddisplay image that is realistic for a better viewing environment.

More generally, to the best of the applicants' knowledge, no one hasimplemented the use of three dimensional color tables in 3D colorprocessing to improve image quality for video images, or in 3D colorprocessing for gamut mapping to larger color gamut displays than aparticular image standard, or in gamut mapping to smaller color gamutdisplays than a particular image standard, or in 3D color mapping todisplays with secondary color capability and more than three colors thatare primary or secondary, using visual models of the human visual systemor otherwise. Currently, standard color processing for displays uses onedimensional tables, 3×3 matrices or matrix mathematics that allowsoutput definition of a small number of colors like RGBCYMW.

3D color tables have been implemented for color calibration, but in suchcircumstances, the tables are small (e.g., 7×7×7). These 3Dlook-up-tables are used instead of one dimensional tables and 3×3matrices because the small 3D look-up-tables are generally faster,albeit at the expense of some loss of precision. In any case,significant color improvement or enhancements to deliver color “looks,”or gamut mapping or mapping to displays with secondary or more thanthree primary colors with such small tables is not possible.

Another problem in certain types of image rendering devices is that theoutputs of the primary color light sources are not stable. This isparticularly true for image rendering devices that use organic lightemitting diodes (OLEDs) as the sources of the primary colors red, green,and blue. A known problem with OLED displays is that the blue OLEDtypically has had a considerably shorter lifespan than the red and greenOLEDs. One measure of OLED life is the decrease of luminance to half thevalue of original brightness. The luminance of currently available blueOLEDs decreases to half brightness in a much shorter time than the redor green OLEDs. During the operation of an OLED display, thisdifferential color change between the blue OLED and the red and greenOLEDs changes the color balance of the display. This change is much moreobjectionable to a viewer than a decrease in overall brightness of thedisplay.

To the best of the applicants' knowledge, the problem of managing theoverall lifespan of OLED displays has not be solved adequately, whichhas led to significant delays in product introduction in themarketplace. There is therefore a need to provide a solution thatmanages the overall quality and lifespan of the relative luminances ofthe red, green and blue OLEDs in a display device.

SUMMARY

A color-enhanced image display, television, or projection that maintainscertain known colors and optimizes colorfulness and contrast will havethe highest visual perceptual quality if and only if the rendering isaccomplished wherein the input RGB colors are processedinter-dependently. This requires the use of a three-dimensional colorlook-up table, also referred to herein as a 3D LUT. The colorenhancement may entail increased brightness and/or a larger or smallercolor gamut, depending upon the particular image display or projector.In prior art image displays and projectors in which traditional matricesand one dimensional color tables operate independently on the RGB inputcolors, a brighter display is not possible without affecting hue. Forexample, blue skies will be shifted towards purple, flesh tones will bealtered in unpredictable ways, and many other color artifacts may bepresent, depending upon the content of the particulardisplayed/projected image. The use of 3D color look-up tables enablesbrighter, higher contrast, and more colorful image displays andprojections without color artifacts. Using methods of the presentinvention, this can be accomplished for image displays or projectorswhich have color gamuts about the same as that of a given colorstandard, or larger than the standard, or smaller than the standard. Thecolor rendering of such image displays or projectors can be enhancedusing three dimensional tables with differing methods in each volume andwith visual models.

In one aspect of the invention, a first method of producing a colorimage is provided comprising providing input image data from an imagesource such as a camera; generating an at least three-dimensionallook-up table of values of input colors and output colors, wherein thevalues in the lookup table convert the input image color data to outputimage color data in an image rendering unit; loading the at leastthree-dimensional look-up table into an image color renderingcontroller; loading the input image data into the imaging colorrendering controller; processing the input image data through the atleast three-dimensional look-up table to produce output color valuesstored at the addresses in the at least three-dimensional look-up table;and outputting the output color values to the image rendering unit toproduce an output image that is perceived to have at least one ofenhanced brightness, enhanced contrast, and enhanced colorfulnesscompared to the input image.

The values in the lookup table may be calculated based upon a visualmodel of the human visual system and they may include modeling toimprove the perceived brightness or contrast or colorfulness fordifferent viewing environments. The at least one of enhanced brightness,enhanced contrast, or enhanced colorfulness introduced by the at leastthree dimensional look-up-table may produce a chosen artistic perceptionin the output image. The image rendering unit may have an expanded colorgamut greater than the color gamut of the input image data, wherein theoutput colors to the image rendering unit utilize the expanded colorgamut, or the image rendering unit may have a reduced color gamutsmaller than the color gamut of the input image data, wherein the outputcolors to the image rendering unit utilize the smaller color gamut. Theinput image data may contain memory colors and non-memory colors, andthe method may include identifying the memory colors in the input imagedata to be substantially maintained, characterizing the memory colorsand non-memory colors with respect to their chromaticities, andproducing an image with substantially maintained memory colors using theimage rendering unit. In such circumstances, the perceived colorfulness,brightness, and contrast of the non-memory colors are changeddifferently than perceived colorfulness, brightness, and contrast of thememory colors. They may be increased more than perceived colorfulness,brightness, and contrast of the memory colors. In one embodiment, theperceived colorfulness, brightness, and contrast of the non-memorycolors are increased more than perceived colorfulness, brightness, andcontrast of the memory colors. Generating the at least three-dimensionallook-up table may include computing enhanced lightness, chroma, and huefor the memory colors using a non-linear enhancement function. Theenhancement function may be a sigmoidal function. More than one at leastthree-dimensional look-up table for the color transformation of thenon-memory colors and the memory colors may be generated and used. Eachof the at least three dimensional look-up tables may be optimized for adifferent viewing environment of the image rendering unit. The methodmay further include providing a sensor for measuring the ambient lightin the viewing environment.

The input image data may be of a first color standard, and the methodmay further include converting the input image data of the first inputcolor standard into an input color specification for inputting into thethree-dimensional look-up table. The at least three-dimensional look-uptable may have at least three input colors and/or at least three outputcolors. The at least three output colors may be any combination ofprimary colors as independent light sources or secondary colors definedas combinations of primary colors. The at least three dimensionallook-up table may be losslessly compressed to reduce storage use inmemory of the image color rendering controller. The method may furtherinclude calibrating the image rendering unit by measuring the colorresponse of the image rendering unit, and then modifying the outputimage data either by additional processing after the at leastthree-dimensional look-up-table or by including the required calibrationin the at least three-dimensional look-up-table.

The image color rendering controller may be contained within the imagerendering unit, or it may be external to the image rendering unit. Anauxiliary imaging device controller may be in communication with theimage color rendering controller and the image rendering unit. The imagerendering unit may be selected from, but not limited to a projector, atelevision, a computer display, and a game display, and may use DMD,plasma, liquid crystal, liquid crystal-on-silicon modulation, or directmodulation of the light source. The light source may be an LED, OLED,laser, or lamp light sources. Without limitation, the image colorrendering controller may be in communication with at least one of acable TV set-top box, a video game console, a personal computer, acomputer graphics card, a DVD player, a Blu-ray player, a broadcaststation, an antenna, a satellite, a broadcast receiver and processor,and a digital cinema.

The image rendering unit may include an algorithm for colormodification, wherein the at least three-dimensional look-up tablefurther comprises processing the input image data to compensate for thecolor modification performed by the image rendering unit. The imagerendering unit may include an algorithm for creating secondary colorsfrom primary colors, and the at least three-dimensional look-up tablefurther comprises compensating for the color modification performed bythe addition of the secondary colors in the image rendering unit.

The at least three-dimensional look-up table may further includeprocessing the input image data to increase perceived color, brightness,and contrast to compensate for the reduction in perceived color,brightness, and contrast caused by the algorithm for color modificationin the image rendering unit. The at least three-dimensional look-uptable may contain a transformation from a suboptimal viewing environmentto an improved viewing environment including the visual adaptation ofthe human visual system. The at least three-dimensional look-up tablemay include the definition of secondary colors, and may further containenhanced lightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of the secondarycolors by the image rendering unit. The at least three-dimensionallook-up table may further include processing the input image data toinclude chromatic adaptation of the human visual system to a specifiedwhite point that increases the brightness of the image rendering unit.

The instant method may be used in the display or projection of twodimensional (2D) or “three dimensional” (3D) images. The 3D images aretypically produced by providing 2D stereo images simultaneously or inrapid sequence taken from two perspectives, so as to provide theobserver with the illusion of depth perception. The image rendering unitmay be a “3D” unit. By way of illustration, and not limitation, the unitmay be e.g., an autostereoscopic display, or it may include a polarizingfilter to separate the 2D stereo images being projected and directed tothe eyes of an observer using polarization glasses, or it may include ashuttering mechanism to separate the 2D stereo images being projectedand directed to the eyes of an observer using time synced shutterglasses. In any case, both sets of 2D images may be processed accordingto the instant method to deliver 3D images that are perceived by anobserver to have enhanced brightness, and/or enhanced contrast, and/orenhanced colorfulness.

In another aspect of the invention, an additional method of producing acolor image is provided, the method comprising providing input imagedata of a first color gamut and an image rendering unit of a second,expanded or reduced color gamut; generating an at leastthree-dimensional look-up table of values of input colors and outputcolors, wherein the values in the lookup table expand or reduce theinput image data to encompass the second color gamut of the imagerendering unit; loading the at least three-dimensional look-up tableinto an image color rendering controller; loading the input image datainto the imaging color rendering controller; processing the input imagedata through the at least three-dimensional look-up table using theinput image data as addresses into the at least three-dimensionallook-up table to produce output image data from the output color valuesstored at the addresses in the at least three-dimensional look-up table;and outputting the output image data to the image rendering unit toproduce an output image that is perceived to have at least one ofenhanced brightness, enhanced contrast, and enhanced colorfulnesscompared to the input image. This method may also include the variousaspects and/or steps described above for the first method.

In another aspect of the invention, the models may include visual modelsof HVS perceptual adaptation to produce a projected or displayed imagethat appears as it would in a more optimal, well lit viewingenvironment. The image processing may include correcting for low levellighting of the surrounding environment and/or indoor or outdoor ambientlight added to the displayed image. More specifically, a method ofproducing a color image by an image rendering unit in a sub-optimalviewing environment is provided, the method comprising generating an atleast three-dimensional look-up table of values of input colors andoutput colors, the table containing a transformation from a suboptimalviewing environment to an improved viewing environment; loading the atleast three-dimensional look-up table into an image color renderingcontroller; loading the input image data into the image color renderingcontroller; processing the input image data through the at leastthree-dimensional look-up table using the input image data as addressesinto the at least three-dimensional look-up table to produce outputimage data from the output color values stored at the addresses in theat least three-dimensional look-up table; and outputting the outputimage data to the image rendering unit. This method may further includethe various aspects and/or steps described above for the first method.The improved viewing environment may be such that an observer mayperceive the color image to have more color, contrast, or brightness.

In yet another aspect of the invention, a method of producing a colorimage by an image rendering unit is provided, the method comprisinggenerating an at least three-dimensional look-up table of values ofinput colors and output colors, the three-dimensional look-up tablecontaining the definition of secondary colors or more than three primarycolors; loading the at least three-dimensional look-up table into animage color rendering controller; loading the input image data into theimage color rendering controller; processing the input image datathrough the at least three-dimensional look-up table using the inputimage data as addresses into the at least three-dimensional look-uptable to produce output image data from the output color values storedat the addresses in the at least three-dimensional look-up table; andoutputting the output image data to the image rendering unit to producean output image that is perceived to have at least one of enhancedbrightness, enhanced contrast, and enhanced colorfulness compared to theinput image. This method may also include the various aspects and/orsteps described above for the first method.

The secondary colors or more than three primary colors may be explicitlydefined, or the secondary colors or more than three primary colorsimplied in the design of a three in by three out look-up table for twoconditions. In either instance, measured responses of the imagerendering unit may be used to define the three-dimensional look-uptable, or mathematics provided by a manufacturer of the image renderingunit may be used to define the three-dimensional look-up table.Alternatively, an open definition of how the secondary colors or morethan three primary colors are used may be provided. This method may alsoinclude the various aspects and/or steps described above for the firstmethod.

In another aspect of the invention, the problem of displaying orprojecting an image that is optimal in human visual perceptual termsregardless of the ambient light and background environment of the imageis solved by using visual models to enhance the perceived colorfulness,contrast, or brightness of the image, thereby improving the perceivedquality of the image. The visual models of human visual perception maybe used to create look-up tables of at least three dimensions to processthe image to be displayed. Memory colors of the image may be preserved.The method may further include performing empirical visual studies todetermine the dependence of the preference of colorfulness, contrast, orbrightness on the ethnicities of the human observers, and defining theperceived quality of the image for each nationality of human observers.The method may further include adjusting the colorfulness, contrast, orbrightness of the image based upon one of the ethnicities of the humanobservers. The method may further include generating an at leastthree-dimensional look-up table of values of input colors and outputcolors, the three-dimensional look-up table adjusting the colorfulness,contrast, or brightness of the image to match the enhanced appearance ofanalog film systems or digital systems designed for cinemas. The methodmay further include adjusting the colorfulness, contrast, or brightnessof the image to produce a chosen artistic perception in the image.

In another aspect of the invention, a method of producing a color imageby an OLED display is provided that manages the overall quality andlifespan of the relative luminances of the red, green and blue OLEDs inthe display. The method comprises providing input image data andproviding the OLED display having at least three OLEDs, each OLED beingof a different primary color; generating an at least three-dimensionallook-up table of values of input colors and output colors, wherein thevalues in the lookup table convert the input image data to output imagecolor data of the OLED display in a manner that optimally manages thequality of the image and the lifetime of the at least three OLEDs;loading the at least three-dimensional look-up table into an image colorrendering controller; loading the input image data into the imagingcolor rendering controller; processing the input image data through theat least three-dimensional look-up table to produce output color valuesstored at the addresses in the at least three-dimensional look-up table;and outputting the output image data to produce the image by the OLEDdisplay. The values in the look-up table may be calculated based upon avisual model of the human visual system. This method may further includethe various aspects and/or steps described above for the first method.

The at least three OLEDs may be a red OLED, a green OLED, and a blueOLED. In such an instance, managing the quality of the image and thelifetime of the OLEDs may further include adding a white primary andmapping predetermined amounts of the grey component of RGB pixel valuesto the white primary to reduce the usage of RGB and extend the life ofthe red, green, and blue OLEDS. Alternatively, managing the quality ofthe image and the lifetime of the OLEDs may comprise adding otherprimary colors and mapping predetermined amounts of the RGB pixel valuesto the other primary colors to reduce the usage of RGB and extend thelife of the red, green, and blue OLEDS. The method may further compriseoperating the at least three OLEDs such that a first OLED does not reachend of life sooner than the other OLEDs, and the image quality of eachof the OLEDs is reduced about equally over time without perceivedartifacts or appearances predominantly of one of the OLED colors.

The method may be further comprised of having a controlled degradationof image quality due to changes in the outputs of at least one of theOLEDs, wherein the change of quality at any given point in time has theleast loss in perceived quality. The controlled degradation may betracked by accumulating and using usage data for all of the OLEDs. Thecontrolled degradation may be performed on the entire image over time,or on at least one portion of the image over time. The controlleddegradation may be performed by substantially maintaining the brightnessof the image while gradually reducing color saturation of the image overtime, or by reducing color saturation of the image to a greater extentin image pixels of low color saturation than in image pixels of highcolor saturation, or by substantially maintaining the brightness of theimage while reducing color saturation gradually using adaptive onedimensional tables on each of the primary colors. The one dimensionaltables on each primary color may be calculated using a qualitydegradation model. The quality degradation model may average among onedimensional tables that are pre-designed to provide the targeted imagequality at specific OLED lifetimes. The one dimensional tables may beproduced by interpolation between a one dimensional table for when theOLEDs are initially operated and a one dimensional table for when theOLEDs are at the ends of their useful lifetimes.

In another aspect of the invention, in an image display, television, orprojector, the problem of achieving an expanded or maximum color gamutby temporally combining R, G, and B during an image frame duty cycle toincrease brightness while maintaining saturated pure R, G, and B colorsis solved by calculating the combinations of R, G, and B that maintain aphysical or perceived input color in a given viewing environment therebymaintaining physical or perceived color saturation and achievingincreased brightness. The calculated combinations are implemented in a3D look-up table.

In any of the above aspects of the invention, the color image to beproduced may contain “memory colors” as defined herein, and non-memorycolors. In general, the memory colors of the image that is produced arepreserved. The methods may include identifying the memory colors in theinput image data to be substantially maintained, characterizing thememory colors and non-memory colors with respect to their chromaticitiesin the image rendering unit, and producing an image comprising humanvisual system perceptually accurate memory colors using the imagerendering unit. The perceived colorfulness, brightness and contrast ofthe non-memory colors are increased more than perceived brightness andcontrast of the memory colors. In one embodiment, generating the atleast three-dimensional look-up table may includes computing enhancedlightness, chroma, and hue for the memory colors using a sigmoidalenhancement function. More than one at least three-dimensional look-uptable may be generated for the color transformation of the non-memorycolors and the memory colors. Some or all of the at least threedimensional look-up tables may be optimized for a different viewingenvironment of the image rendering unit. In such an instance, the methodmay further include selecting one of the at least three-dimensionallook-up tables for loading into the image color rendering controllerbased upon the viewing environment of the image rendering unit. A sensormay be provided for measuring the ambient light in the viewingenvironment.

In a related aspect of the invention, the problem of displaying an imagethat simultaneously has high brightness and high colorfulness of amajority of colors (and particularly high saturation colors), whilemaintaining realistic “memory colors” is solved by adding white light orany combination of multiple R, G, B colors by combining R, G, and B forsome portion of the duty cycle of the image projection time, accordingto a 3D look-up table, which replaces the lost colorfulness of addingcolor combinations and at the same time preserves flesh tones and otherknown memory colors. The image data is processed with a 3D look-up tablein a manner that that increases the perceived colorfulness, brightness,and contrast while preserving flesh tones and other known memory colors.The 3D look-up table is created to produce the improved image quality.Visual models may be used to perform the image processing.

In any of the above aspects of the invention, the methods may furthercomprise converting the input image data of a first input color standardinto an input color specification for inputting into thethree-dimensional look-up table.

The solutions to the above problems may entail multi-dimensional look-uptables, with three dimensional look-up tables being one example. The atleast three dimensional lookup table may have three or more input colorsand three or more output colors. The output dimension may be differentfrom the input dimension, such as having RGBCYMW(red-green-blue-cyan-magenta-yellow-white) output values in an RGBtable, i.e. three values of input and seven values of output. The numberof outputs may also be greater than three due to the display having morethan three physical colors, i.e., more than three primary colors such asR, G, and B. In such an instance, the output colors could therefore bethe primary colors or combinations of the four or more colors. Ingeneral, the three or more than three output colors are any combinationof primary colors as independent light sources or secondary colorsdefined as combinations of primary colors. The at least threedimensional look-up table(s) may be losslessly compressed to reducestorage use in a memory of the image color rendering controller.

More specifically, according to the present disclosure, a method ofdisplaying an image containing memory colors and saturated colors isprovided comprising identifying the memory colors in input image data tobe substantially maintained, characterizing the memory colors withrespect to their chromaticities, and generating a three-dimensionallook-up table for a color transformation of saturated and memory colors.The three-dimensional look-up table is loaded into an imaging devicecontroller, and input image data is loaded into the imaging devicecontroller. The input image data is processed with an algorithm usingthe three-dimensional look-up table to produce output image data. Theoutput image data is output to an image rendering device, and a highbrightness, high contrast image comprising human visual systemperceptually accurate memory colors is displayed or projected.

In one embodiment, the method includes preprocessing, wherein onedimensional tables and matrices are provided for converting the varietyof possible input color standards into a preferred color input to the 3Dor higher dimensional color look-up-table. This is done for the purposeof making a single or reduced number of 3D or higher dimensional colorlook-up-tables adaptable to different video standards. In anotherembodiment, the algorithm containing the 3D or higher dimensionalmathematics is executed in real time by the central processing unit of acomputer in the image display or projection device so that the need fora 3D color table is obviated. This may be done if the device computer isprovided with adequate computational processing capability and memory.

In another embodiment, the method includes incorporating the variety ofpossible input color standards directly into the creation of the 3D orhigher dimensional color look-up-tables to adapt to different videostandards.

In some circumstances, the image rendering unit (such as, e.g., adisplay or projection device) is provided with some color modificationcapability that is “built in.” For example, the device may provided withan algorithm to add white or secondary colors, resulting in a loss ofcolorfulness, and a distortion in the appearance of memory colors. Insuch circumstances, the output values in the at least three-dimensionallook-up table are determined such that the input image data is processedto compensate for the color modification performed by the imagerendering unit. The method may thus include providing at least 3D colortables to adjust the color data in a manner that shifts it in adirection within the color space that compensates for the built in colormodification that is performed by the image rendering unit. The at leastthree-dimensional look-up table further comprises processing the inputimage data to increase perceived color, brightness, and contrast tocompensate for the reduction in perceived color, brightness, andcontrast caused by the algorithm for color modification in the imagerendering unit. In a more specific instance in which the image renderingunit includes an algorithm for creating secondary colors from primarycolors, the at least three-dimensional look-up table may furthercomprise compensating for the color modification performed by theaddition of the secondary colors in the image rendering unit. The valuesin the at least three dimensional lookup table may also be determinedsuch that the at least three-dimensional look-up table further comprisesprocessing the input image data to include chromatic adaptation of thehuman visual system to a specified white point that increases thebrightness of the image rendering unit. The at least three-dimensionallook-up table may also adjust the colorfulness, contrast, or brightnessof the image to be produced to match the enhanced appearance of analogfilm systems or digital systems designed for cinemas.

According to the present disclosure, there is further provided a devicefor producing a color image. The device is comprised of a computerincluding a central processing unit and a memory in communicationthrough a system bus. The memory may be a random access memory, or acomputer readable storage medium. The memory contains an at least threedimensional lookup table. In one aspect of the invention, the at leastthree dimensional lookup table contains values of input colors andoutput colors, wherein the values in the lookup table convert an inputimage color data set to output image color data in an image renderingunit that is connectable to the device.

In another aspect of the invention, the at least three dimensionallookup table may be produced by an algorithm for transforming inputimage data comprising memory colors and non-memory colors to a visualcolor space, and computing enhanced lightness, chroma, and hue for thememory colors and non-memory colors in the visual color space. Thealgorithm to produce the three dimensional lookup table may be containedin the memory.

In another aspect of the invention, the at least three dimensionallookup table includes values of input colors and output colors, whereinthe values in the lookup table convert a first color gamut of an inputimage data set to encompass a second expanded or reduced color gamut ofan image rendering unit that is connectable to the device.

In another aspect of the invention, the at least three dimensionallookup table contains a transformation from a suboptimal viewingenvironment to an improved viewing environment including the visual andchromatic adaptation of the human visual system.

In another aspect of the invention, the at least three dimensionallookup table contains the definition of secondary colors, and enhancedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of secondarycolors by an image rendering unit that is connectable to the device.

In another aspect of the invention wherein the image is perceived by ahuman observer, the memory may contain a visual model to enhance theperceived colorfulness, contrast, or brightness of the image.

In any of the above aspects of the invention, the device may furtherinclude the image rendering unit in communication with the computer. Theimage rendering unit may be selected from a projector, a television, acomputer display, and a game display, and may use DMD, plasma, liquidcrystal, liquid crystal-on-silicon modulation (LCOS), or directmodulation of the light source and LED, organic light emitting diode(OLED), laser, or lamp light sources. The device may further comprise anauxiliary imaging device including at least one of a cable TV set-topbox, a video game console, a personal computer, a computer graphicscard, a DVD player, a Blu-ray player, a broadcast station, an antenna, asatellite, a broadcast receiver and processor, and a digital cinema. Oneof a liquid crystal display, a plasma display, and a DMD projector maybe in communication with the auxiliary device. The device may furthercomprise a communication link to a source of input image data.

The at least three-dimensional look-up table includes the definition ofsecondary colors, and contains enhanced lightness, chroma, and hues toincrease perceived colorfulness, contrast, or brightness to compensatefor the loss in perceived colorfulness, contrast, or brightness due toaddition of the secondary colors by the image rendering unit.Alternatively or additionally, the at least three-dimensional look-uptable may contain a transformation from a suboptimal viewing environmentto an improved viewing environment including the visual and chromaticadaptation of the human visual system.

The memory of the device may contain a set of at least three dimensionallookup tables; each table of the set may be optimized for a differentviewing environment of the image rendering unit. The device may beprovided with a sensor for measuring the ambient light in the viewingenvironment.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be provided with reference to the followingdrawings, in which like numerals refer to like elements, and in which:

FIGS. 1A-1D are illustrative, two-dimensional schematic diagrams ofvarious prior art ways for processing input color data to produce outputcolor data for rendering a color image;

FIG. 2 is a schematic diagram of aspects of the instant method forprocessing input color data to produce output color data for rendering acolor image;

FIG. 3 is a chromaticity diagram that depicts color gamuts of the DCIand HD709 standards, and color gamuts of various media and/or imagingdevices;

FIG. 4 is a perspective view of a three-dimensional color spacedepicting a series of color gamuts of an image display, projector, ortelevision in which the gamuts have been sequentially reduced by theaddition of white to the R, G, and B primary colors thereof;

FIG. 5 is a schematic diagram of a device for producing a color image;

FIG. 6 is a flowchart depicting the steps of one algorithm forgenerating a three-dimensional lookup table for the purposes of thisinvention; and

FIG. 7 is a flowchart depicting one method for producing a color imagein accordance with the present disclosure;

FIG. 8 is a schematic diagram of one mathematical flowchart forproducing a color image in accordance with the present invention, whichincludes color output calibration.

The present invention will be described in connection with a preferredembodiment, however, it will be understood that there is no intent tolimit the invention to the embodiment described. On the contrary, theintent is to cover all alternatives, modifications, and equivalents asmay be included within the spirit and scope of the invention as definedby the appended claims.

DETAILED DESCRIPTION

For a general understanding of the present invention, reference is madeto the drawings. In the drawings, like reference numerals have been usedthroughout to designate identical elements. In describing the presentinvention, a variety of terms are used in the description. Standardterminology is widely used in image processing, display, and projectionarts. For example, one may refer to the International LightingVocabulary, Commission Internationale de l'éclairage (CIE), 1987 fordefinitions of standard terms in the fields of color science andimaging. One may also refer to Billmeyer and Saltzman's PRINCIPLES OFCOLOR TECHNOLOGY, 3^(RD) Ed, Roy S. Berns, John Wiley & Sons, Inc.,2000; and Color Appearance Models, Mark D. Fairchild, Wiley-IS&T,Chichester, UK (2005).

In order to fully describe the invention, as used in the presentdisclosure, certain terms are defined as follows:

-   Brightness—attribute of a visual perception according to which an    area appears to emit, or reflect, more or less light.-   BT.709—abbreviated reference to ITU Radiocommunication Sector    (ITU-R) Recommendation BT.709, a standard for the format of    high-definition television.-   Chromaticity—normalized CIE Tristimulus values often used to    visualize the color gamuts of devices in a Chromaticity diagram,    such as that shown in FIG. 3.-   CIECAM02—the most recent color model adopted by the International    Commission on Illumination, or Commission internationale de    l'éclairage (CIE), published in 2002.-   Color—A specification of a color stimulus in terms of operationally    defined values, such as three tristimulus values.-   Color Space—A three-dimensional space in which each point therein    corresponds to a color.-   Colorfulness—Attribute of a visual perception according to which the    perceived color of an area appears to be more or less chromatic.-   Contrast—In the perceptual sense, assessment of the difference in    appearance of two or more parts of a field seen simultaneously or    successively.-   DCI Standard—a color standard for digital cinema systems created by    Digital Cinema Initiatives, LLC a joint venture of major motion    picture studios formed in 2002. The standard is included in the    publication, “Digital Cinema System Specification,” Version 1.2    approved by Digital Cinema Initiatives, LLC Mar. 7, 2008.-   Display—An imaging device which forms an image from discrete lighted    elements at a surface thereof.-   Color Gamut—The range of colors producible with a set of inks,    lights, or other colorants. A color gamut may be described in terms    of a particular region of a color space.-   Hue—Attribute of a visual perception according to which an area    appears to be similar to one of the colors, red, yellow, green, and    blue, or to a combination of adjacent pairs of these colors    considered in a closed ring.-   Memory color—a color of an object in an image for which an observer    may consciously or unconsciously observe and make a judgment as to    whether the color of the object is accurate, based upon the    observer's memory of previous experiences observing the object.    Examples of memory colors are flesh (human skin) tones, the green of    grass, the blue of the sky, the yellow of a banana, the red of an    apple, and grey scale. The accurate rendering of colors associated    with commercial products and registered trademarks, such as “Kodak    yellow”, “IBM blue,” and “John Deere green” may be important to some    viewers/users of images, and are also examples of memory colors. It    is further noted that the perceived appearance of memory colors may    be influenced by the context in which they are seen by an observer.-   Primary colors—The colors of the individual light sources, including    all color filters, that are used to create a color image in an image    rendering unit.-   Projector—An imaging device which forms an image by delivering and    in some instances focusing light on a distant, separate surface such    as a wall or screen.-   RGBCYMW—in the use of any of these capital letters in combination    herein, they stand for red, green, blue, cyan, yellow, magenta, and    white, respectively.-   Rendering an image—providing an image for observation, either via an    image display that forms an image from discrete lighted elements at    a surface thereof, or via an image projector that forms an image by    delivering and in some instances focusing light on a distant,    separate surface such as a wall or screen.-   Saturation—Colorfulness of an area judged in proportion to its    brightness.-   Secondary colors—Linear or non-linear combinations of the primary    colors of an image rendering unit that can be controlled    independently from the primary colors.-   Tristimulus values—Amounts of the three reference color stimuli, in    a given trichromatic system, required to match the color of a    stimulus being considered.-   White—a set of three values of primary colors, typically red, green,    and blue, that may be added to a color in a portion of an image,    thereby in effect adding white to the color to brighten the color.

It is further noted that as used herein, a reference to a threedimensional lookup table or a 3DLUT is meant to indicate a table of atleast three dimensions, unless otherwise indicated. A lookup table maybe multidimensional, i.e., it may have three or more input colors andthree or more output colors.

FIG. 2 is an illustrative, two-dimensional schematic diagram depictingthe full multi-dimensional capability of an at least three dimensionalcolor table 54 used in processing input color data to produce outputcolor rendering a color image. For the sake of simplicity ofillustration, the diagram 420 of FIG. 2 depicts only a 2D rendition ofan at least 3D color table 54 of the present invention. Any point,and/or any region in the full color space can be changed independently.The small squares 422 represent locations in the color space in which nochange in color is made. These locations may be memory color locations,such as flesh tones.

In other regions 424, selective increases in contrast, colorfulness, andbrightness may be made. The larger squares 426 in these regions 424represent locations where colorfulness, contrast, and brightness areincreased. Any local color or color region, such as a flesh tone region,can be chosen for unique color processing. In one embodiment, a 3D colortable may contain output values for every input RGB color, which for 12bits per color would be 4096×4096×4096 independent colors, therebyproviding 68.7 billion local color choices. In another embodiment, a 3Dcolor table size can be reduced by using the most-significant bits ofthe input colors to define the 3D color table locations and performingmulti-linear or other multi-dimensional interpolation using theleast-significant bits of the input colors.

It is to be understood that the while the squares 422 and 426 are meantto indicate various color regions, the borders of the squares are notmeant to indicate sharply defined boundaries of such regions. Asdescribed previously, these regions may be modeled using a probabilitydistribution that provides a smooth transition from regions in the colorspace that are outside of the regions defined by the squares.

For example, the various regions may be defined by Gaussian boundariesthat are smoothly connected by probability functions. In defining thecolor output values in the at least 3D LUT 54, volume derivatives may beused that displace the color (R, G, B) vectors in different amounts.Within memory color regions, the color vectors have a lesserdisplacement, or possibly none at all, while other color regions havelarger displacements to increase their contrast, colorfulness, andbrightness.

The full table may be very large. For example, a large table results ifthe input color is 24-bit (i.e. 8 bits each for R, G, and B), and theoutput includes white and is 32 bit (i.e. 8 bits each for R, G, B, andW). Referring to FIG. 5, this large 3D LUT 54 may be used if the memory36 of the image color rendering controller is sufficiently large, andresults in the fastest color processing. However, if the memory 36 islimited in size, but sufficient computational capacity is available inthe CPU 34, multi-dimensional interpolation may be used to reduce thesize of the 3D LUT 54. In this particular example, for each respectiveprimary input color, bits 3 through 8 may be used to define and addressthe 3D LUT 54. Multi-dimensional interpolation may then be used withbits 1 and 2 to define the output colors that occur between the outputcolors associated with the 8 vertices of the cube in the 3D LUT 54defined by bits 3 through 8.

The color gamut of an image rendering unit, such as a display,television, and/or projector is defined by the maximum colors that canbe produced by that image rendering unit with combinations of itsprimary colors. FIG. 3 shows the color gamuts of various image renderingtechnologies compared to the CCIR709 color standard 404 and the DCIcolor standard 402. FIG. 3 shows that displays such as LED projectors(gamut 406), OLED displays (gamut 408), Digital Cinema projectors (gamut410) and televisions with more than 3 primary colors (gamut 412) havelarger color gamuts than the CCIR709 color standard (gamut 404) fordigital media distribution, thus illustrating the need to map thesmaller CCIR709 color standard to the larger color gamut of thesedisplay types. All other international color standards for consumerdigital color media are similar to CCIR709 and therefore exhibit thesame need to map these standards to the larger color gamut of thedisplay types in FIG. 3. In the methods of the present invention, thisis done while simultaneously preserving memory colors, and optimizingthe particular device for viewing in a particular environment, andtaking into account adaptation of the human visual system. FIG. 3 alsoshows that the DCI “Hollywood” color standard is significantly largerthan the color gamut 414 of an infinite set of lasers, and thereforelarger than any possible display or image rendering unit, thusillustrating the need to map the larger input to the smaller color gamutof any display type including a professional digital cinema projector.

In a color image rendering unit, such as a display, television, and/orprojector, in order to achieve maximum brightness with a single opticalsystem and single image modulator, the multiple RGB channels may becombined for some portion of time during image frames. Adding thesemultiple RGB channels during an image frame duty cycle will increase thebrightness of the image, but will also reduce the colorfulness bydesaturating the pure RGB colors. FIG. 4 is a perspective view of athree-dimensional CIECAM02J L*a*b* opponent color space 10 depicting aseries of color gamuts of an image display, projector, or television inwhich the gamuts have been sequentially reduced by the addition of whiteto the R, G, and B primary colors thereof. The outer (coarsest squares)color gamut 12 is the color gamut of one exemplary image projectorhaving its primary colors produced by red, green, and blue LEDs. Thewire frame color gamut 11 represents the CCIR709 video color standard.The successively finer squares solids 14, 16, 18, and 20 represent thecolor gamuts resulting from the addition of 6.25%, 12.5%, 25%, and 50%white, respectively. For the sake of simplicity of illustration, 2Dprojections of the color gamuts 11-20 are provided on the a*b* plane asrespective closed curves 11A-20A. The color gamut 12/12A of the LEDprimaries has no added white. It can be seen in general from the 3Dperspective renditions and the 2D projections that the addition of whitealways reduces the color gamut of the image device.

However, this does not mean that the addition of white to the images ofthe device cannot be beneficial. It can also be seen that the additionof white at a 6.25% level, as indicated by solid 14 and closed curve14A, results in a color gamut that is approximately equal to the CCIR709color video standard, while at the same time making the image perceivedto be brighter. In an image rendering unit, and particularly in singlemodulation LED displays such as those employing a digital micromirrordevice (DMD), the image is made to appear brighter by the addition ofwhite from combining RGB colors. In digital cinema, this may be done forsome portion of the image frame time. The capabilities of human visualsystem adaptation are thereby exploited to increase the apparentbrightness and lightness contrast of the displayed images.

In one aspect of the present invention, visual models of visualperception by the human visual system are used in determining theoptimum amount of white to add to the colors of the image. The perceivedcolorfulness, contrast, and/or brightness of the image are enhanced,thereby improving the perceived quality of the image. The visual modelsof human visual perception may be used to create look-up tables of atleast three dimensions to process the image to be displayed. The methodsof the present invention may include performing empirical visual studiesto determine the dependence of preference of colorfulness, contrast, orbrightness on the ethnicities of the human observers, and defining theperceived quality of the image for each nationality of human observers.The colorfulness, contrast, or brightness of the image may be adjustedbased upon the preferences of one of the ethnicities of the humanobservers.

FIG. 5 is a schematic diagram of a device for producing a color image,which may be observed by a human observer. The imaging device mayinclude an image rendering unit such as e.g., a television, a display, aprojector, or another unit. Referring to FIG. 5, the imaging device 30may include an image color rendering controller 32 or computer 32 orother processor comprising a central processing unit 34 and a memory 36.As an alternative memory, or in addition to the memory 36, thecontroller 32 may include a computer readable storage medium 38 such asa hard disk. These components are in communication through a system bus39. The device 39 may be further comprised of an image rendering unit40, which may be an image display or projector, such as a liquid crystaldisplay 42; a plasma display 44; a digital mirror device (DMD) 46including a DMD 80, a lamp 82, and color wheel 84; or a digital mirrordevice 48 including a DMD 80, and red, green, and blue LED's, OLEDs orlasers 86, 87, and 88.

The imaging device 30 may process input image data that is stored on thestorage medium 38, or the imaging device 30 may receive input image datafrom an external device or source 50. The external source 50 maycomprise an Internet connection or other network or telecommunicationsconnection, such that the input image data is transmitted through suchconnection.

The imaging device 30 may be adapted to a system for displaying orprojecting an image in a variety of ways, depending upon the particularapplication. In some embodiments, the imaging device 30 may be providedas an integrated system comprising the controller 32 and the imagerendering unit (display or projector) 40, which only needs to beconnected to a source 50 of image input data. In another embodiment, theimaging device 30 may be separate from the image rendering unit 40, andin communication with the image rendering unit 40 through a network ortelecommunications connection as described above. The imaging device 30may be provided comprising the image color rendering controller 32, afirst port (not shown) for connection to a source 50 of image inputdata, and a second port (not shown) for connection to the imagerendering unit 40. This configuration is particularly useful forretrofitting to projection or flat screen televisions that receivesignals via a cable that is connected to a broadcast source of imageinput data (e.g., “cable TV programming”). In such circumstances, thecable carrying input image data 50 could be disconnected from the imagerendering unit 40, and the imaging device 30 could be placed in linebetween them to perform the image processing of the present invention.

In other embodiments, the imaging device 30 may be in communicationwith, or integrated into an auxiliary device 60 or auxiliary imagingdevice controller 60, which is in communication with the image renderingunit 40. The imaging device controller 60 may be, without limitation, anaudio/video processor, a cable TV set-top box, a video game console, apersonal computer (PC), a computer graphics card of a PC, or a DVD orBlu-ray player. In another embodiment, the imaging device 30 may beintegrated into the electronics and processing components of a broadcaststation, a broadcast antenna, receiver or processor, or a digital cinematheatre. In another embodiment, the device 30 may be integrated into thehardware and software of media creation, preparation, and productionequipment, such as equipment used in the production of DVDs of moviesand television programs, or the production of digital cinema fordistribution to theaters. Broadcast stations, digital cinema theaters,and media production equipment may all be comprised of an auxiliaryimaging device controller 60.

The memory 36 of the device 30 may contain a set of at least threedimensional lookup tables 54; each table of the set may be optimized fora different viewing environment of the image rendering unit 40. Thedevice 30 may be provided with a sensor 70 for measuring the ambientlight in the viewing environment of the image rendering unit 40, or inthe case of a projector 46 or 48, in the viewing environment of theprojected image. The memory 36 may contain a visual model of theperception of the human visual system that may be used to enhance theperceived colorfulness, contrast, or brightness of the produced image.

FIG. 6 is a flowchart depicting an algorithm for generating athree-dimensional lookup table to improve the perceived colorfulness,contrast or brightness in non-memory colors, while preserving to ahigher degree the color accuracy of memory colors. The algorithm 100 ofFIG. 6 may be used to perform step 210 of the method 200 of FIG. 7.Additionally, the algorithm 100 is applicable to other image renderingdevices that use DMD, plasma, liquid crystal, liquid crystal-on-siliconmodulation, or direct modulation of the light source, and using LED,OLED, laser, or lamp light sources.

Referring to FIG. 6, in operation 110, the RGB input values of the inputimage data are “reverse gamma” corrected to compensate for thenon-linearity of this data, thereby producing linearized scalar RGBvalues. (The original input data is supplied with the expectation thatit will be used in a display or projector that may have a gamma value ofabout 2.2, for example.) In operation 120, the outer product of thescalar RGB values and the projector matrix is taken to express the inputimage data as CIE XYZ tristimulus values. In operation 130, thetristimulus values are converted to a visual color space. Thetransformation to a visual color space enables perceptual modeling to beperformed, which characterizes the interdependencies of color, contrast,and brightness, and allows the perception of memory colors to bepreserved. The visual color space may be an opponent color space thataccurately models constant perceived hue, and has the dimensions oflightness, yellow-blue, and red-green.

In operation 140, the visual color space predicted appearance attributesof lightness, chroma, and hue are computed. In operation 150, theenhanced lightness, chroma, and hue for colors to be rendered arecomputed. Operation 150 may include steps 152, 154, and 156 formaintaining memory colors in the rendering of the image.

In applications in which there are specific memory colors to bepreserved, operation 150 of the method 100 may include steps 152, 154,and 156. More specifically, the method 100 may include the step 152 ofidentifying the memory colors in the input image data 50 to besubstantially maintained. This may be done based on intuition andexperience and/or market research data. It is known that observers of animage depicting human subject matter (such as a movie or televisionprogram) will find it objectionable if the colors of the skin, and facesin particular, of the humans in the image do not match those colors thatthey have in their respective memories of how the humans should look.They will perceive the humans as “not looking right,” if they are toopink, orange, dark, light, etc. In like manner, certain other memorycolors, such as “grass green” and “sky blue” must be rendered so as toappear as the observers remember them from experience. Regardless of howsatisfactory the other colors in the image appear, the observers willfind a product that does not render memory colors accurately to not beperceptually optimal, and will likely not buy the product, whether theproduct is an imaging device such as a television, or a movie to beviewed in a theater.

Once the memory colors are chosen, they are characterized with respectto their chromaticities in step 154 from both empirical data and theperceptual context in which they are seen. For instance, it is wellunderstood that humans remember green grass and blue sky as moresaturated than the actual stimuli. And, within reason, no matter thecolor of an illuminant, humans will remember a banana to appear to be acertain yellow (which may also be a memory color). Furthermore, thesememory colors are not distributed across the extent of perceptual colorin any systematic way. Hence, their representations must necessarily bemade in a multivariant, three dimensional, statistical sense and theirrendering accomplished in a purely appearance or vision based colorspace. Algorithms may be employed using visual mathematics which ensurethat the memory colors are specified in terms of perceived colors.

In step 156, the enhanced lightness, chroma, and hue for non memorycolors and memory colors are also computed. It is noted that in thecolor space of the input image data, a given memory color is not asingle point within the space. To the contrary, memory colors areregions within the color space that are to be left at least perceptuallyunchanged, or much less changed during the color transformations of theinstant methods to produce enhanced images. By way of example, thememory color “flesh tone” is a range of colors corresponding to thecolors of very dark-skinned peoples of African ethnicity to very lightskinned Caucasians or Asians. Accordingly, the memory colors areidentified and characterized such that the colors within this regionwill be left unchanged or minimally changed in the colortransformations.

Additionally, these memory colors may be characterized as not havingrigid, discrete boundaries; this may be done so that in the colortransformations to be performed, there is not a discontinuity in thedegree of color change at a boundary of a memory color, as explainedpreviously with reference to FIG. 2. In one embodiment, the memory colormay be modeled using a probability distribution that provides a smoothtransition from regions in the color space that are non-memory colors tothe region defined as the particular memory color. Any smoothingfunction that changes the local multi-dimensional derivatives smoothlywill be satisfactory. The probability distribution may use non-linearenhancement functions. An exemplary overall non-linear function that maybe used is

${Output} = {0.0001 + \left( \frac{1.5 \times {Input}^{EXP}}{0.5 + {Input}^{EXP}} \right)}$

In operation 160, the enhanced lightness, chroma, and hue of the visualcolor space are converted to enhanced CIE XYZ tristimulus values. Inoperation 170, the enhanced CIE XYZ tristimulus values are converted toenhanced RGB scalar values with “white channel.” In operation 180, gammacorrection of the enhanced RGB scalar values is performed to produce a3DLUT containing enhanced RGB values with white channel. The 3DLUT maythen be used in the method 200 of FIG. 7.

FIG. 6 concludes with a simple statement 101 of the net effect of theoperations 110-180. The 3DLUT, which is of at least three dimensions, iscreated as a discrete sampling of the visual model andcontrast/color/brightness HVS perceptual improvement mathematics, andmay include preservation of memory colors. Referring also to FIG. 5, theat least 3DLUT 54 may be generated by the CPU 34 of the imaging system30 according to an algorithm 52 stored in memory 36 or on the readablestorage medium 38. Alternatively, the at least 3DLUT 54 may be generatedby another computing system and uploaded to the system computer 32. Thealgorithm 52 of FIG. 5 for generating the at least 3DLUT 54 may bealgorithm 100 of FIG. 6.

FIG. 7 is a flowchart depicting one method for rendering a color imagein accordance with the present disclosure. The method may be performedusing the imaging system 30 depicted in FIG. 5. Referring again to FIGS.5 and 7, in step 210, the 3DLUT 54, which may be produced according tothe algorithm 100 of FIG. 6, is loaded into the memory 36 or thereadable storage medium 38 of the imaging device 30. In step 220, theinput image data from the source 50 is communicated to the CPU 34. Theinput image data may be of a first input color standard, and may beconverted into an input color specification for inputting into the atleast three-dimensional look-up table. In step 230, the input image datais processed with an algorithm 56 that may be stored in memory 36, usingthe at least three-dimensional look-up table 54 to produce renderedimage data. In step 240, the rendered image data is output to the imagedisplay/projection device 40, and a high brightness, high contrast, andhigh colorfulness image is displayed or projected in step 250. The imagemay include human visual system perceptually accurate memory colors. Themethod 100 may be repeatedly performed at a high rate on sequences ofimage input data, such as at the rate of 24 or 48 “frames per second”used in digital cinema, or such as at the rate of 30, 60, 120 or 240frames per second used in consumer displays.

Referring again to FIG. 5, and in one embodiment, the 3DLUT 54 of inputcolors and output colors may contain, or the values therein may bedetermined from, the definition of secondary colors, and enhancedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of secondarycolors by the image rendering unit 40. In another embodiment, the 3DLUT54 of input colors and output colors may contain, or be determined from,a transformation from a suboptimal viewing environment to an improvedviewing environment including the visual adaptation of the human visualsystem.

In another embodiment, the method may include providing input image data50 of a first color gamut, and an image rendering unit 40 having asecond, expanded or reduced color gamut. The 3DLUT 54 of values of inputcolors and output colors is generated, wherein the values in the 3DLUT54 are calculated based upon a visual model of the human visual system,thereby expanding the input image data 50 to encompass the second colorgamut of the image rendering unit 40.

In another aspect of the invention, the image rendering unit 40 may beprovided with some color modification capability that is built in orembedded in hardware or software. For example, the device may beprovided with an algorithm to add white or secondary colors, resultingin a loss of colorfulness, and a distortion in the appearance of memorycolors. In such circumstances, the output values in the 3DLUT 54 aredetermined such that the input image data 50 is processed to compensatefor the color modification performed by the image rendering unit 40. Themethod may thus include providing the 3DLUT 54 to adjust the color datain a manner that shifts it in a direction within the color space thatcompensates for the embedded color modification that is performed by theimage rendering unit 40. The 3DLUT 54 further comprises processing theinput image data to increase perceived color, brightness, and contrastto compensate for the reduction in perceived color, brightness, andcontrast caused by the algorithm for color modification in the imagerendering unit 40.

In a more specific instance in which the image rendering unit 40includes an algorithm for creating secondary colors from primary colors,the 3DLUT 54 may further comprise compensating for the colormodification performed by the addition of the secondary colors in theimage rendering unit 40. The values in the 3DLUT 54 may also bedetermined such that the 3DLUT 54 further comprises processing the inputimage data 50 to include chromatic adaptation of the human visual systemto a specified white point that increases the brightness of the imagerendering unit 40.

In another aspect of the invention, the image rendering unit 40 mayunintentionally contain some color modification capability resultingfrom variation in one or more parameters of the unit 40. For example, ifthe image rendering unit 40 is an OLED display, then over the life ofthe display, color modification may occur due to the differing lifespans between blue OLED and red and green OLEDs of the display, asdescribed previously herein. During the operation of the OLED display,the differential color change between the blue OLED and the red andgreen OLEDs will change the color balance of the display if nocountermeasures are instituted.

In such circumstances, the output values in the 3DLUT 54 may bedetermined such that the input image data 50 is processed to compensatefor the predicted decrease in luminance of the blue OLED. The method maythus include providing the 3DLUT 54 to adjust the color data in a mannerthat shifts it in a direction within the color space that compensatesfor decreasing blue OLED luminance. The 3DLUT 54 further comprisesprocessing the input image data to increase perceived color, brightness,and contrast to compensate for the reduction in perceived color,brightness, and contrast caused by the continual loss of blue OLEDluminance.

The 3DLUT 54 may also adjust the colorfulness, contrast, or brightnessof the image to be produced to appear as it would in an image from ananalog film system or digital system used in cinemas. It is known thatfilm is generally not designed to reproduce color as the eye sees it atthe filming site. (A color gamut 416 for film is shown in FIG. 3.)Instead, the colors in film images have increased contrast and increasedcolorfulness in anticipation of the viewing environment in which thefilm images will be observed. It is also known that digital systems aimto match the look of film images. Accordingly, the 3DLUT may be designedto provide the same effect in a cinema.

The production of the 3D LUT 54 is not limited only to the algorithm 100of FIG. 6. Bit depth modification and interpolation as described hereinmay also be applied to all of the applications herein which include theuse of 3DLUTs. The 3DLUT may vary in bit depth, depending upon thecapacity of the memory 32 and the processing power of the CPU 34. In oneembodiment, the 3DLUT may be a twelve bit table with 4096×4096×4096discrete addresses containing three or more color values ofpredetermined bit precision. In another embodiment, some bits of thetable may be used for interpolation between adjacent values. Forexample, the final two bits of respective adjacent table values may beused in interpolating colors between them. Other methods ofmulti-dimensional interpolation are known, and are included inembodiments of implementing the 3DLUT. Additionally, the input data maycontain more than three primary colors such as RGB. For example, theinput data may contain RGBCMY (wherein C=cyan, M=magenta, and Y=yellow),or some lesser combination such as RGBCM. In such an instance, the 3DLUTcould have outputs of RGBCMYW.

Depending upon the particular application, the algorithm 100, or otheralgorithms that may further include bit depth modification andinterpolation, may be used to produce more than one 3DLUT. One factorthat may be used to determine the values in the 3DLUT is the set ofcharacteristics of the display or projection device. Referring again toFIG. 5, different 3DLUTs 54 may be produced for different image outputdevices, for example, an LCD display 42, a lamp-and-color-wheel DMDprojector 44, and an LED DMD projector 46. The characteristics of thedisplay or projection device 40 include the “color engine” of thedevice, and whether it includes only RGB as the primary colors, or hasmore than three colors. The 3DLUTs 54 may be losslessly compressed toreduce storage use in the memory 36 of the image color renderingcontroller 30.

Other factors pertain to the “surround,” i.e., the viewing environmentof the display or projection device 40, such as the ambient lighting ofthe room in which the display or projection occurs, and the lightingand/or surface immediately surrounding the display/projection screen. Ingeneral, the 3DLUT values provide a displayed/projected image havingmore contrast, brightness, and colorfulness for any “surround”, i.e.viewing environment; for example, a particular room lighting and anyconversion from that room lighting to an improved room lighting. If theroom lighting is darker or brighter than a desired level, the generationof the 3DLUT 54 may include a visual adaptation transformation toproduce a perception of improved viewing environment. The visualadaptation transformation is based upon visual models that may includemodels of the adaptation of the human vision to viewing environments.

For example, in a dark room there is essentially no ambient lighting(other than minimal safety and exit lighting), but using a visualadaptation transformation to increase contrast and colorfulness in amanner analogous to that used in motion picture print film to providethe perception of an improved viewing environment to an observer. As theroom lighting increases and the image brightness increases to about thesame level, the adaptation transformation is still needed because it theroom lighting is still not as bright as daytime outdoor lighting, whilethe ambient lighting must be compensated for. In summary, the visualadaptation transformation implemented in the 3DLUT 54 uses visualadaptation models to produce the effect of improved viewing environment.

Other factors in generating the 3DLUT 54 may include a knowledge of thedifferent sensitivities to colorfulness in different worldwide regions,or the intended use of the displayed/projected images; for example,whether the images are viewed in a video game that is being played, orviewed as a movie or television program.

These multiple 3DLUTs 54, or a subset of them may be stored in thememory 36 of the computer 32 of the device 30. Additionally, data on theviewing environment factors 58 may be stored in memory. The image device30 may include a keyboard (not shown) or other input device to access auser interface (not shown) that may be displayed on the display orprojector 40 (or other user interface screen). The user interface mayoffer the capability of inputting data on the viewing environmentfactors 58, and/or other factors such that the optimum 3DLUT is selectedfrom the stored 3DLUTs 54 for the particular display or projector 40 andviewing environment. In that manner, the most perceptually optimalimages are provided to the user by the system 30. The 3DLUTs 54 areeffective for the enhancement of a variety of images, including but notlimited to games, movies, or personal photos. Additionally, someimprovement of grey scale images is attained by the resulting contrastand brightness enhancement thereof.

The 3DLUT 54 may be produced according to variants of the method 200such that it has additional or alternative characteristics. The valuesin the 3DLUT 54 may be provided to convert a first color gamut of aninput image data set 50 to encompass a second expanded or reduced colorgamut of an image rendering unit 40 that is connectable to the device30. The 3DLUT 54 may contain a transformation from a suboptimal viewingenvironment to an improved viewing environment in which the color imageis to be observed, including the visual and chromatic adaptation of thehuman visual system. The 3DLUT 54 may contain the definition ofsecondary colors, and enhanced lightness, chroma, and hues to increaseperceived colorfulness, contrast, or brightness to compensate for theloss in perceived colorfulness, contrast, or brightness due to additionof secondary colors by an image rendering unit 40 that is connectable tothe device 30.

In another aspect of the invention, the methods of producing a colorimage may include input color standard transformation and color outputcalibration of the image rendering device that is in use. This is bestunderstood with reference to FIG. 8, which is a schematic diagram of analternative method 300 for producing a color image, which includes suchcolor output calibration. The diagram includes color output calibrationoperations 350, 360, and 370; however, for the sake of clarity, theentire method depicted in FIG. 8 will be described, with reference alsoto FIGS. 6 and 7.

In operation 310 (“Gamma1”), the input values of R, G, and B are reversegamma corrected to compensate for the non-linearity of this input datastandard, thereby producing linearized scalar values R, B, and G. Thiscorrection may be done using the respective one dimensional lookuptables 311, 312, and 313. The input values of R, G, and B may be between8 and 12 bits (314 in FIG. 8) inclusive. The output values of R, G, andB, may have 16 bit resolution (315 in FIG. 8), depending upon thearchitecture of the image color rendering controller 32, and also uponthe need for the greater bit depth of the imaging standards being used.The input R, G, and B values may be provided from various devices, suchas a video camera having an output in accordance with standard BT.709.In such circumstances, the value of gamma used in the correction may be2.2. The input R, G, and B values may be provided in accordance withother imaging standards, and other values of gamma and other 1D lookuptables 311, 312, and 313 may consequently be used in the reverse gammacorrection as needed. In operation 320 (“Color Transform”), every colorvalue in the image data stream 319 represented by a unique R, G, and B,combination is then operated on by a 3×3 matrix determined by theparticular imaging standard being used to perform a color transformationto R_(i), G_(i), and B_(i) values that are linearized scalar valuesreferenced to the standard BT.709. The R_(ii), G_(ii), and B_(ii) valuesmay be provided with a bit resolution of up to 16 bits as indicated inFIG. 8.

In operation 330, (“Gamma2”), the values of R_(ii), G_(ii), and B_(ii)are gamma encoded to re-introduce a non-linearity into the processeddata, thereby producing gamma encoded values R_(iii), B_(iii), andG_(iii) for input to the 3D color tables. This encoding may be doneusing the respective one dimensional lookup tables 331, 332, and 333,using a gamma encoding factor of 1/2.2, in one embodiment. Other factorsmay be suitable, depending upon the particular imaging standards beingused. The resulting values of R_(iii), B_(iii), and G_(iii) may bereduced to 10 bit resolution as shown in FIG. 8, to enable sufficientlyfast subsequent processing using the 3D color tables 54. The gammaencoding enables a reduction in the number of bits from 16 for lineardata to much less for gamma encoded data, such as 10 bits, withoutartifacts. This makes the at least 3D table much smaller. It iseffective to use fewer gamma encoded bits because the eye sees imagedata in a manner analogous to a gamma encoder.

In operation 340, the three dimensional color tables 54 are used toprocess the R_(iii)B_(iii)G_(iii) data to produce output imageR_(iv)B_(iv)G_(iv)W_(iv) data for display or projection. In thisembodiment, the table 54 is 3D in (RGB) and 4D out (RGBW). Other tablestructures of at least three dimensions may be used, depending upon theparticular application. Additionally, for the sake of simplicity ofillustration, there is only one table 54 shown in FIG. 8; however, it isto be understood that there is a first 3D LUT for determining R_(iv), asecond 3D LUT for determining G_(iv), a third 3D LUT for determiningB_(iv), and a fourth 3D LUT for determining W_(iv), where a whitechannel is implemented. In this embodiment, the white could be for anOLED display, or the signal that drives the combination of RGB to makethe image rendering device brighter. Alternatively, the white could bereplaced with cyan, or some other color in a four-color image renderingdevice, such as a four-color TV. The R_(iv)B_(iv)G_(iv)W_(iv) data maybe provided at a 12 bit resolution as indicated in FIG. 8.

At this point, the R_(iv)B_(iv)G_(iv)W_(iv) data, including the additionof white for increased brightness or color management of OLED devicesmay represent a generic display with typical color primaries andlinearity. Additionally, however, further operations may be performed tofurther optimize the R_(iv)B_(iv)G_(iv)W_(iv) data by calibration forthe particular image rendering unit (display or projector) 40 that is inuse. The measurement or specification of this particular image renderingunit 40 can be done in manufacturing on done on-site by a technicianwith conventional linearity and primary color measuring tools.

Referring again to FIG. 8, in operation 350 (“Gamma3”), theR_(iv)B_(iv)G_(iv)W_(iv) data is first reverse gamma-corrected toproduce R_(v)B_(v)G_(v)W_(v) data. This correction may be done using therespective one dimensional lookup tables 351, 352, 353, and 354. Theoutput values of R_(v), G_(v), B_(v), and W_(v) may have 16 bits. Thevalue of gamma used in the correction may be 2.2, or another value inaccordance with the gamma encoder 310.

In operation 360 (“Color Calibration”), every color value in the imagedata stream 359 represented by a unique R_(v), G_(v), B_(v), and, and inmany cases, W_(v) combination is then operated on by a 4×4 matrix. This4×4 matrix is produced for and is unique to the particular imagerendering unit 40 of FIG. 5 that is in service. The matrix is calculatedfrom measured or specified values that define the color primaries of theparticular image rendering unit 40. The purpose of the operation is toconvert from the assumed or generic color primaries in the at least 3Dcolor table to the actual ones in the image rendering unit 40. Thevisual effect is to adjust for white and the rest of the colors so theyare not “tinted” (e.g., a little yellow or blue), because the imagerendering unit may have slightly different color primaries than wereassumed in creating the at least 3D table. For standard televisions orprojectors, those assumptions are in accordance with the aforementionedBT.709 standard, because most TVs, displays, and projectors adhere tothis standard. A given image rendering device may be tinted, e.g., moreyellow, however so the calibration matrix compensates for thatvariation. The R_(vi), G_(vi), B_(vi), and W_(vi) values may be providedwith a bit resolution of up to 16 bits.

In operation 370, (“Calibration”), the R_(vi), G_(vi), B_(vi), andW_(vi) values are gamma encoded to introduce the correct non-linearityinto the processed data for the image rendering unit 40, therebyproducing the R_(vii), G_(vii), B_(vii), W_(vii) values that, when usedby the particular image rendering unit 40 to project or display theimage, produce chosen non-linearity defined by the 3D table. Thisencoding may be done using the respective one dimensional lookup tables371, 372, 373, and 374. In one embodiment, a gamma encoding factor of1/2.2 may be used. Other factors may be suitable, depending upon theparticular imaging rendering unit 40. The resulting values of R_(vii),G_(vii), B_(vii), W_(vii) may be output having between 8 and 12 bitresolution as indicated in FIG. 8.

It is, therefore, apparent that there has been provided, in accordancewith the present invention, methods and devices for producing a colorimage. Having thus described the basic concept of the invention, it willbe rather apparent to those skilled in the art that the foregoingdetailed disclosure is intended to be presented by way of example only,and is not limiting. Various alterations, improvements, andmodifications will occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested hereby, and are within thespirit and scope of the invention. Additionally, the recited order ofprocessing elements or sequences, or the use of numbers, letters, orother designations therefore, is not intended to limit the claimedprocesses to any order except as may be specified in the claims.Accordingly, the invention is limited only by the following claims andequivalents thereto.

We claim:
 1. A method of producing a color image, the method comprising:a. providing input image data; b. generating an at leastthree-dimensional look-up table of values of input colors and outputcolors, wherein the values in the lookup table convert the input imagecolor data to output image color data in an image rendering unit; c.loading the at least three-dimensional look-up table into an image colorrendering controller; d. loading the input image data into the imagingcolor rendering controller; e. processing the input image data throughthe at least three-dimensional look-up table to produce output colorvalues stored at the addresses in the at least three-dimensional look-uptable; and f. outputting the output color values to the image renderingunit to produce an output image that is perceived to have at least oneof enhanced brightness, enhanced contrast, and enhanced colorfulnesscompared to the input image; wherein the input image data containsmemory colors and non-memory colors, and the method further comprisesidentifying the memory colors in the input image data to besubstantially maintained, characterizing the memory colors andnon-memory colors with respect to their chromaticities, and producing animage with substantially maintained memory colors using the imagerendering unit.
 2. The method of claim 1, wherein the at least one ofimproved viewing quality of brightness, contrast, and colorfulnessintroduced by the at least three dimensional look-up-table produce achosen artistic perception in the output image.
 3. The method of claim1, wherein the image rendering unit is of an expanded color gamutgreater than the color gamut of the input image data, and wherein theoutput colors to the image rendering unit utilize the expanded colorgamut.
 4. The method of claim 1, wherein the image rendering unit is ofa smaller color gamut than the color gamut of the input image data, andwherein the output colors to the image rendering unit utilize thesmaller color gamut.
 5. The method of claim 1, wherein perceivedcolorfulness, brightness, and contrast of the non-memory colors arechanged differently than perceived colorfulness, brightness, andcontrast of the memory colors.
 6. The method of claim 5, whereinperceived colorfulness, brightness and contrast of the non-memory colorsare increased more than perceived colorfulness, brightness, and contrastof the memory colors.
 7. The method of claim 1, wherein generating theat least three-dimensional look-up table includes computing lightness,chroma, and hue for the memory colors using a non-linear enhancementfunction.
 8. The method of claim 1, further comprising generating morethan one at least three-dimensional look-up table for the colortransformation of the non-memory colors and the memory colors.
 9. Themethod of claim 1, further comprising generating more than one at leastthree-dimensional look-up table for the color transformation of thenon-memory colors and the memory colors, wherein each of the at leastthree dimensional look-up tables is optimized for a different viewingenvironment of the image rendering unit.
 10. The method of claim 9,further comprising selecting one of the at least three-dimensionallook-up tables for loading into the image color rendering controllerbased upon the viewing environment of the image rendering unit.
 11. Themethod of claim 10, further comprising providing a sensor for measuringthe ambient light in the viewing environment.
 12. The method of claim 1,wherein the input image data is of a first color standard, and themethod further comprises converting the input image data of the firstinput color standard into an input color specification for inputtinginto the three-dimensional look-up table.
 13. The method of claim 1,wherein the at least three-dimensional look-up table has at least threeinput colors.
 14. The method of claim 1, wherein the at leastthree-dimensional look-up table has at least three output colors. 15.The method of claim 14, wherein the at least three output colors are anycombination of primary colors as independent light sources or secondarycolors defined as combinations of primary colors.
 16. The method ofclaim 1, wherein the at least three dimensional look-up table islosslessly compressed to reduce storage use in a memory of the imagecolor rendering controller.
 17. The method of claim 1, furthercomprising calibrating the image rendering unit by measuring the colorresponse of the image rendering unit, and then modifying the outputimage data by one of additional processing after the at leastthree-dimensional look-up-table or including the required calibration inthe at least three-dimensional look-up-table.
 18. The method of claim 1,wherein the image color rendering controller is contained within theimage rendering unit.
 19. The method of claim 1, wherein the imagingcolor rendering controller is external to the image rendering unit. 20.The method of claim 1, wherein an auxiliary imaging device controller isin communication with the image color rendering controller and the imagerendering unit.
 21. The method of claim 1, wherein the image colorrendering controller is in communication with the image rendering unitwhich is selected from a projector, a television, a computer display,and a game display, the image rendering unit using DMD, plasma, liquidcrystal, liquid crystal-on-silicon modulation, or direct modulation ofthe light source, and using LED, OLED, laser, or lamp light sources. 22.The method of claim 1, wherein the image color rendering controller isin communication with at least one of a cable TV set-top box, a videogame console, a personal computer, a computer graphics card, a DVDplayer, a Blu-ray player, a broadcast station, an antenna, a satellite,a broadcast receiver and processor, and a digital cinema.
 23. The methodof claim 1, wherein the image rendering unit includes an algorithm forcolor modification, wherein the at least three-dimensional look-up tablefurther comprises processing the input image data to compensate for thecolor modification performed by the image rendering unit.
 24. The methodof claim 23, wherein the image rendering unit includes an algorithm forcreating secondary colors from primary colors, and the at leastthree-dimensional look-up table further comprises compensating for thecolor modification performed by the addition of the secondary colors inthe image rendering unit.
 25. The method of claim 23, wherein the atleast three-dimensional look-up table further comprises processing theinput image data to increase perceived color, brightness, and contrastto compensate for the reduction in perceived color, brightness, andcontrast caused by the algorithm for color modification in the imagerendering unit.
 26. The method of claim 1, wherein the at leastthree-dimensional look-up table contains a transformation from asuboptimal viewing environment to an improved viewing environmentincluding the visual adaptation of the human visual system, wherein theimage rendering unit is located in the suboptimal viewing environment,and wherein the output image in the image rendering unit is perceived toappear as it would in the improved viewing environment.
 27. The methodof claim 1, wherein the at least three-dimensional look-up tableincludes the definition of secondary colors, and contains improvedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of the secondarycolors by the image rendering unit.
 28. The method of claim 1, whereinthe color image is a 3D color image comprised of two 2D stereo imagesprovided simultaneously.
 29. A method of producing a color image, themethod comprising: a) providing input image data; b) generating an atleast three-dimensional look-up table of values of input colors andoutput colors, wherein the at least three-dimensional look-up table isbased upon a model of human visual system perceptual adaptation, and thevalues in the lookup table convert the input image color data to outputimage color data in an image rendering unit; c) loading the at leastthree-dimensional look-up table into an image color renderingcontroller; d) loading the input image data into the imaging colorrendering controller; e) processing the input image data through the atleast three-dimensional look-up table to produce output color valuesstored at the addresses in the at least three-dimensional look-up table;and f) outputting the output color values to the image rendering unit toproduce an output image that is perceived to have at least one ofimproved viewing quality of brightness, contrast, and colorfulnesscompared to the input image; wherein the at least three-dimensionallook-up table further comprises processing the input image data toinclude chromatic adaptation of the human visual system to a specifiedwhite point that increases the brightness of the image rendering unit.30. A method of producing a color image, the method comprising: a)providing input image data of a first color gamut and an image renderingunit of a second, different color gamut; b) generating an at leastthree-dimensional look-up table of values of input colors and outputcolors, wherein the at least three-dimensional look-up table is basedupon a model of human visual system perceptual adaptation, and thevalues in the lookup table change the input image data to encompass thesecond color gamut in the image rendering unit; c) loading the at leastthree-dimensional look-up table into an image color renderingcontroller; d) loading the input image data into the imaging colorrendering controller; e) processing the input image data through the atleast three-dimensional look-up table using the input image data asaddresses into the at least three-dimensional look-up table to produceoutput image data from the output color values stored at the addressesin the at least three-dimensional look-up table; and f) outputting theoutput image data to the image rendering unit to produce an output imagethat is perceived to have at least one of improved viewing quality ofbrightness, contrast, and colorfulness compared to the input image;wherein the color image contains memory colors and non-memory colors,and the method comprises identifying the memory colors in the inputimage data to be substantially maintained, characterizing the memorycolors and non-memory colors with respect to their chromaticities, andproducing an image with substantially maintained memory colors using theimage rendering unit.
 31. The method of claim 30, wherein the at leastone of improved viewing quality of brightness, contrast, andcolorfulness introduced by the at least three dimensional look-up-tableproduce a chosen artistic perception in the output image.
 32. The methodof claim 30, wherein the image rendering unit is of an expanded colorgamut greater than the color gamut of the input image data, and whereinthe output colors to the image rendering unit utilize the expanded colorgamut.
 33. The method of claim 30, wherein the image rendering unit isof a smaller color gamut than the color gamut of the input image data,and wherein the output colors to the image rendering unit utilize thesmaller color gamut.
 34. The method of claim 30, wherein perceivedcolorfulness, brightness, and contrast of the non-memory colors arechanged differently than perceived colorfulness, brightness, andcontrast of the memory colors.
 35. The method of claim 30, whereinperceived colorfulness, brightness, and contrast of the non-memorycolors are increased more than perceived colorfulness, brightness, andcontrast of the memory colors.
 36. The method of claim 30, whereingenerating the at least three-dimensional look-up table includescomputing enhanced lightness, chroma, and hue for the memory colorsusing a non-linear enhancement function.
 37. The method of claim 30,further comprising generating more than one at least three-dimensionallook-up table for the color transformation of the non-memory colors andthe memory colors.
 38. The method of claim 30, further comprisinggenerating more than one at least three-dimensional look-up table forthe color transformation of the non-memory colors and the memory colors,wherein each of the at least three dimensional look-up tables isoptimized for a different viewing environment of the image renderingunit.
 39. The method of claim 38, further comprising selecting one ofthe at least three-dimensional look-up tables for loading into the imagecolor rendering controller based upon the viewing environment of theimage rendering unit.
 40. The method of claim 39, further comprisingproviding a sensor for measuring the ambient light in the viewingenvironment.
 41. The method of claim 30, further comprising convertingthe input image data of a first input color standard into an input colorspecification for inputting into the three-dimensional look-up table.42. The method of claim 30, wherein the at least three-dimensionallook-up table has at least three input colors.
 43. The method of claim30, wherein the at least three-dimensional look-up table has at leastthree output colors.
 44. The method of claim 43, wherein the at leastthree output colors are any combination of primary colors as independentlight sources or secondary colors defined as combinations of primarycolors.
 45. The method of claim 30, wherein the at least threedimensional look-up table is losslessly compressed to reduce storage usein a memory of the image color rendering controller.
 46. The method ofclaim 30, further comprising calibrating the image rendering unit bymeasuring the color response of the image rendering unit, and thenmodifying the output image data by one of additional processing afterthe at least three-dimensional look-up-table or including the requiredcalibration in the at least three-dimensional look-up-table.
 47. Themethod of claim 30, wherein the image color rendering controller iscontained within the image rendering unit.
 48. The method of claim 30,wherein the imaging color rendering controller is external to the imagerendering unit.
 49. The method of claim 30, wherein an auxiliary imagingdevice controller is in communication with the image color renderingcontroller and the image rendering unit.
 50. The method of claim 30,wherein the image color rendering controller is in communication withthe image rendering unit selected from a projector, a television, acomputer display, and a game display, the image rendering unit usingDMD, plasma, liquid crystal, liquid crystal-on-silicon modulation, ordirect modulation of the light source, and using LED, OLED, laser, orlamp light sources.
 51. The method of claim 30, wherein the image colorrendering controller is in communication with at least one of a cable TVset-top box, a video game console, a personal computer, a computergraphics card, a DVD player, a Blu-ray player, a broadcast station, anantenna, a satellite, a broadcast receiver and processor, and a digitalcinema.
 52. The method of claim 30, wherein the image rendering unitincludes an algorithm for color modification, and wherein the at leastthree-dimensional look-up table further comprises processing the inputimage data to compensate for the color modification performed by theimage rendering unit.
 53. The method of claim 52, wherein the imagerendering unit includes an algorithm for creating secondary colors fromprimary colors, and the at least three-dimensional look-up table furthercomprises compensating for the color modification performed by theaddition of the secondary colors in the image rendering unit.
 54. Themethod of claim 52, wherein the at least three-dimensional look-up tablefurther comprises processing the input image data to increase perceivedcolor, brightness, and contrast to compensate for the reduction inperceived color, brightness, and contrast caused by the algorithm forcolor modification in the image rendering unit.
 55. The method of claim30, wherein the at least three-dimensional look-up table contains atransformation from a suboptimal viewing environment to an improvedviewing environment including the visual adaptation of the human visualsystem, wherein the image rendering unit is located in the suboptimalviewing environment, and wherein the output image in the image renderingunit is perceived to appear as it would in the improved viewingenvironment.
 56. The method of claim 30, wherein the at leastthree-dimensional look-up table includes the definition of secondarycolors, and contains improved lightness, chroma, and hues to increaseperceived colorfulness, contrast, or brightness to compensate for theloss in perceived colorfulness, contrast, or brightness due to additionof the secondary colors by the image rendering unit.
 57. The method ofclaim 30, wherein the color image is a 3D color image comprised of two2D stereo images provided simultaneously.
 58. A method of producing acolor image, the method comprising: a) providing input image data of afirst color gamut and an image rendering unit of a second, differentcolor gamut; b) generating an at least three-dimensional look-up tableof values of input colors and output colors, wherein the at leastthree-dimensional look-up table is based upon a model of human visualsystem perceptual adaptation, and the values in the lookup table changethe input image data to encompass the second color gamut in the imagerendering unit; c) loading the at least three-dimensional look-up tableinto an image color rendering controller; d) loading the input imagedata into the imaging color rendering controller; e) processing theinput image data through the at least three-dimensional look-up tableusing the input image data as addresses into the at leastthree-dimensional look-up table to produce output image data from theoutput color values stored at the addresses in the at leastthree-dimensional look-up table; and f) outputting the output image datato the image rendering unit to produce an output image that is perceivedto have at least one of improved viewing quality of brightness,contrast, and colorfulness compared to the input image; wherein the atleast three-dimensional look-up table further comprises processing theinput image data to include chromatic adaptation of the human visualsystem to a specified white point that increases the brightness of theimage rendering unit.
 59. A method of producing a color image by animage rendering unit, the method comprising: a) generating an at leastthree-dimensional look-up table of values of input colors and outputcolors, wherein the at least three-dimensional look-up table is basedupon a model of human visual system perceptual adaptation, and the tablecontains a transformation from a suboptimal viewing environment to animproved viewing environment; b) loading the at least three-dimensionallook-up table into an image color rendering controller; c) loading inputimage data into the image color rendering controller; d) processing theinput image data through the at least three-dimensional look-up tableusing the input image data as addresses into the at leastthree-dimensional look-up table to produce output image data from theoutput color values stored at the addresses in the at leastthree-dimensional look-up table; e) outputting the output image data tothe image rendering unit located in the suboptimal viewing environment;and f) producing an output image in the image rendering unit that isperceived to appear as it would in the improved viewing environment;wherein the color image contains memory colors and non-memory colors,and the method comprises identifying the memory colors in the inputimage data to be substantially maintained, characterizing the memorycolors and non-memory colors with respect to their chromaticities, andproducing an image with substantially maintained memory colors using theimage rendering unit.
 60. The method of claim 59, wherein the outputimage data outputted to the image rendering unit produces a chosenartistic perception in the output image.
 61. The method of claim 59,wherein the image rendering unit is of an expanded color gamut greaterthan the color gamut of the input image data, and wherein the outputcolors to the image rendering unit utilize the expanded color gamut. 62.The method of claim 59, wherein the image rendering unit is of a smallercolor gamut than the color gamut of the input image data, and whereinthe output colors to the image rendering unit utilize the smaller colorgamut.
 63. The method of claim 59, wherein perceived colorfulness,brightness, and contrast of the non-memory colors are changeddifferently than perceived colorfulness, brightness, and contrast of thememory colors.
 64. The method of claim 59, wherein perceivedcolorfulness, brightness and contrast of the non-memory colors areincreased more than perceived colorfulness, brightness, and contrast ofthe memory colors.
 65. The method of claim 59, wherein generating the atleast three-dimensional look-up table includes computing enhancedlightness, chroma, and hue for the memory colors using a non-linearenhancement function.
 66. The method of claim 59, further comprisinggenerating more than one at least three-dimensional look-up table forthe color transformation of the non-memory colors and the memory colors.67. The method of claim 59, further comprising generating more than oneat least three-dimensional look-up table for the color transformation ofthe non-memory colors and the memory colors, wherein each of the atleast three dimensional look-up tables is optimized for a differentviewing environment of the image rendering unit.
 68. The method of claim67, further comprising selecting one of the at least three-dimensionallook-up tables for loading into the imaging device controller based uponthe viewing environment of the image rendering unit.
 69. The method ofclaim 68, further comprising providing a sensor for measuring theambient light in the viewing environment.
 70. The method of claim 59,further comprising converting the input image data of an first inputcolor standard into an input color specification for inputting into thethree-dimensional look-up table.
 71. The method of claim 59, wherein theat least three-dimensional look-up table has three or more input colors.72. The method of claim 59, wherein the at least three-dimensionallook-up table has three or more output colors.
 73. The method of claim72, wherein the three or more output colors are any combination ofprimary colors as independent light sources or secondary colors definedas combinations of primary colors.
 74. The method of claim 73, whereinthe at least three dimensional look-up table is losslessly compressed toreduce storage use in a memory of the image color rendering controller.75. The method of claim 59, further comprising calibrating the imagerendering unit by measuring the color response of the image renderingunit, and then modifying the output image data by one of additionalprocessing after the at least three-dimensional look-up-table orincluding the required calibration in the at least three-dimensionallook-up-table.
 76. The method of claim 59, wherein the image colorrendering controller is contained within the image rendering unit. 77.The method of claim 59, wherein the image color rendering controller isexternal to the image rendering unit.
 78. The method of claim 59,wherein an auxiliary imaging device controller is in communication withthe image color rendering controller and the image rendering unit. 79.The method of claim 59, wherein the image color rendering controller isin communication with the image rendering unit selected from aprojector, a television, a computer display, and a game display, theimage rendering unit using DMD, plasma, liquid crystal, liquidcrystal-on-silicon modulation, or direct modulation of the light source,and using LED, OLED, laser, or lamp light sources.
 80. The method ofclaim 59, wherein the image color rendering controller is incommunication with at least one of a cable TV set-top box, a video gameconsole, a personal computer, a computer graphics card, a DVD player, aBlu-ray player, a broadcast station, an antenna, a satellite, abroadcast receiver and processor, and a digital cinema.
 81. The methodof claim 59, wherein the image rendering unit includes an algorithm forcolor modification, and wherein the at least three-dimensional look-uptable further comprises processing the input image data to compensatefor the color modification performed by the image rendering unit. 82.The method of claim 81, wherein the image rendering unit includes analgorithm for creating secondary colors from primary colors, and the atleast three-dimensional look-up table further comprises compensating forthe color modification performed by the addition of the secondary colorsin the image rendering unit.
 83. The method of claim 81, wherein the atleast three-dimensional look-up table further comprises processing theinput image data to increase perceived color, brightness, and contrastto compensate for the reduction in perceived color, brightness, andcontrast caused by the algorithm for color modification in the imagerendering unit.
 84. The method of claim 59, wherein the input image datais of a first color gamut and the image rendering unit is of a second,expanded color gamut; and wherein the values in the lookup table expandthe input image data to encompass the second color gamut of the imagerendering unit.
 85. The method of claim 59, wherein the input image datais of a first color gamut and the image rendering unit is of a second,reduced color gamut; and wherein the values in the lookup table reducethe input image data to encompass the second color gamut of the imagerendering unit.
 86. The method of claim 59, wherein the at leastthree-dimensional look-up table includes the definition of secondarycolors, and contains improved lightness, chroma, and hues to increaseperceived colorfulness, contrast, or brightness to compensate for theloss in perceived colorfulness, contrast, or brightness due to additionof the secondary colors by the image rendering unit.
 87. The method ofclaim 59, wherein the color image is a 3D color image comprised of two2D stereo images provided simultaneously.
 88. A method of producing acolor image by an image rendering unit, the method comprising: a)generating an at least three-dimensional look-up table of values ofinput colors and output colors, wherein the at least three-dimensionallook-up table is based upon a model of human visual system perceptualadaptation, and the table contains a transformation from a suboptimalviewing environment to an improved viewing environment; b) loading theat least three-dimensional look-up table into an image color renderingcontroller; c) loading input image data into the image color renderingcontroller; d) processing the input image data through the at leastthree-dimensional look-up table using the input image data as addressesinto the at least three-dimensional look-up table to produce outputimage data from the output color values stored at the addresses in theat least three-dimensional look-up table; e) outputting the output imagedata to the image rendering unit located in the suboptimal viewingenvironment; and f) producing an output image in the image renderingunit that is perceived to appear as it would in the improved viewingenvironment; wherein the at least three-dimensional look-up tablefurther comprises processing the input image data to include chromaticadaptation of the human visual system to a specified white point thatincreases the brightness of the image rendering unit.
 89. A method ofproducing a color image, the method comprising: a) generating an atleast three-dimensional look-up table of values of input colors andoutput colors, wherein the at least three-dimensional look-up table isbased upon a model of human visual system perceptual adaptation, andcontains the definition of one of secondary colors and more than threeprimary colors; b) loading the at least three-dimensional look-up tableinto an image color rendering controller; c) loading input image datainto the image color rendering controller; d) processing the input imagedata through the at least three-dimensional look-up table using theinput image data as addresses into the at least three-dimensionallook-up table to produce output image data from the output color valuesstored at the addresses in the at least three-dimensional look-up table;e) outputting the output image data to an image rendering unit; and f)producing an output image in the image rendering unit that is perceivedto have at least one of improved viewing quality of brightness,contrast, and colorfulness compared to the input image; wherein thecolor image contains memory colors and non-memory colors, and the methodcomprises identifying the memory colors in the input image data to besubstantially maintained, characterizing the memory colors andnon-memory colors with respect to their chromaticities, and producing animage with substantially maintained memory colors using the imagerendering unit.
 90. The method of claim 89, wherein the at least one ofimproved viewing quality of brightness, contrast, and colorfulnessintroduced by the at least three dimensional look-up-table produce achosen artistic perception in the output image.
 91. The method of claim89, wherein the image rendering unit is of an expanded color gamutgreater than the color gamut of the input image data, and wherein theoutput colors to the image rendering unit utilize the expanded colorgamut.
 92. The method of claim 89, wherein the image rendering unit isof a smaller color gamut than the color gamut of the input image data,and wherein the output colors to the image rendering unit utilize thesmaller color gamut.
 93. The method of claim 89, wherein perceivedcolorfulness, brightness, and contrast of the non-memory colors arechanged differently than perceived colorfulness, brightness and contrastof the memory colors.
 94. The method of claim 89, wherein perceivedcolorfulness, brightness, and contrast of the non-memory colors areincreased more than perceived colorfulness, brightness, and contrast ofthe memory colors.
 95. The method of claim 89, wherein generating the atleast three-dimensional look-up table includes computing the enhancedlightness, chroma, and hue for the memory colors using a non-linearenhancement function.
 96. The method of claim 89, further comprisinggenerating more than one at least three-dimensional look-up table forthe color transformation of the non-memory colors and the memory colors.97. The method of claim 89, further comprising generating more than oneat least three-dimensional look-up table for the color transformation ofthe non-memory colors and the memory colors, wherein each of the atleast three dimensional look-up tables is optimized for a differentviewing environment of the image rendering unit.
 98. The method of claim97, further comprising selecting one of the at least three-dimensionallook-up tables for loading into the image color rendering controllerbased upon the viewing environment of the image rendering unit.
 99. Themethod of claim 97, further comprising providing a sensor for measuringthe ambient light in the viewing environment.
 100. The method of claim89, further comprising converting the input image data of a first inputcolor standard into an input color specification for inputting into thethree-dimensional look-up table.
 101. The method of claim 89, whereinthe at least three-dimensional look-up table has three or more inputcolors.
 102. The method of claim 89, wherein the at leastthree-dimensional look-up table has three or more output colors. 103.The method of claim 102, wherein the three or more output colors are anycombination of primary colors as independent light sources or secondarycolors defined as combinations of primary colors.
 104. The method ofclaim 89, wherein the at least three dimensional look-up table islosslessly compressed to reduce storage use in a memory of the imagecolor rendering controller.
 105. The method of claim 89, furthercomprising calibrating the image rendering unit by measuring the colorresponse of the image rendering unit, and then modifying the outputimage data by one of additional processing after the at leastthree-dimensional look-up-table or including the required calibration inthe at least three-dimensional look-up-table.
 106. The method of claim89, wherein the image color rendering controller is contained within theimage rendering unit.
 107. The method of claim 89, wherein the imagecolor rendering controller is external to the image rendering unit. 108.The method of claim 89, wherein an auxiliary imaging device controlleris in communication with the image color rendering controller the imagerendering unit.
 109. The method of claim 89, wherein the image colorrendering controller is in communication with the image rendering unitselected from a projector, a television, a computer display, and a gamedisplay, the image rendering unit using DMD, plasma, liquid crystal,liquid crystal-on-silicon modulation, or direct modulation of the lightsource, and using LED, OLED, laser, or lamp light sources.
 110. Themethod of claim 89, wherein the image color rendering controller is incommunication with at least one of a cable TV set-top box, a video gameconsole, a personal computer, a computer graphics card, a DVD player, aBlu-ray player, a broadcast station, an antenna, a satellite, abroadcast receiver and processor, and a digital cinema.
 111. The methodof claim 89, wherein the image rendering unit includes an algorithm forcolor modification, and wherein the at least three-dimensional look-uptable further comprises processing the input image data to compensatefor the color modification performed by the image rendering unit. 112.The method of claim 111, wherein the image rendering unit includes analgorithm for creating secondary colors from primary colors, and the atleast three-dimensional look-up table further comprises compensating forthe color modification performed by the addition of the secondary colorsin the image rendering unit.
 113. The method of claim 111, wherein theat least three-dimensional look-up table further comprises processingthe input image data to increase perceived color, brightness, andcontrast to compensate for the reduction in perceived color, brightness,and contrast caused by the algorithm for color modification in the imagerendering unit.
 114. The method of claim 89, wherein the input imagedata is of a first color gamut and the image rendering unit is of asecond, expanded color gamut; and wherein the values in the lookup tableexpand the input image data to encompass the second color gamut of theimage rendering unit.
 115. The method of claim 89, wherein the inputimage data is of a first color gamut and the image rendering unit is ofa second, reduced color gamut; and wherein the values in the lookuptable reduce the input image data to encompass the second color gamut ofthe image rendering unit.
 116. The method of claim 89, wherein the atleast three-dimensional look-up table contains a transformation from asuboptimal viewing environment to an improved viewing environmentincluding the visual adaptation of the human visual system, wherein theimage rendering unit is located in the suboptimal viewing environment,and wherein the output image in the image rendering unit is perceived toappear as it would in the improved viewing environment.
 117. The methodof claim 89, wherein the three-dimensional look-up table has the one ofsecondary colors and more than three primary colors explicitly definedand wherein measured responses of the image rendering unit are used todefine the three-dimensional look-up table.
 118. The method of claim 89,wherein the three-dimensional look-up table has the one of secondarycolors and more than three primary colors explicitly defined and whereinmathematics provided by a manufacturer of the image rendering unit areused to define the three-dimensional look-up table.
 119. The method ofclaim 89, wherein the three-dimensional look-up table has the one ofsecondary colors and more than three primary colors explicitly definedand wherein there is provided an open definition of how the one ofsecondary colors and more than three primary colors are used.
 120. Themethod of claim 89, wherein the three-dimensional look-up table has theone of secondary colors and more than three primary colors implied inthe design of a three in by three out look-up table for two conditions,and wherein measured responses of the image rendering unit are used todefine the three-dimensional look-up table.
 121. The method of claim 89,wherein the three-dimensional look-up table has the one of secondarycolors and more than three primary colors implied in the design of athree in by three out look-up table for two conditions, and whereinmathematics provided by a manufacturer of the image rendering unit areused to define the three-dimensional look-up table.
 122. The method ofclaim 89, wherein the three-dimensional look-up table has the one ofsecondary colors and more than three primary colors implied in thedesign of a three in by three out look-up table for two conditions, andwherein there is provided an open definition of how the secondary colorsor more than three primary colors are used.
 123. The method of claim 89,wherein the color image is a 3D color image comprised of two 2D stereoimages provided simultaneously.
 124. A method of producing a colorimage, the method comprising: a) generating an at leastthree-dimensional look-up table of values of input colors and outputcolors, wherein the at least three-dimensional look-up table is basedupon a model of human visual system perceptual adaptation, and containsthe definition of one of secondary colors and more than three primarycolors; b) loading the at least three-dimensional look-up table into animage color rendering controller; c) loading input image data into theimage color rendering controller; d) processing the input image datathrough the at least three-dimensional look-up table using the inputimage data as addresses into the at least three-dimensional look-uptable to produce output image data from the output color values storedat the addresses in the at least three-dimensional look-up table; e)outputting the output image data to an image rendering unit; and f)producing an output image in the image rendering unit that is perceivedto have at least one of improved viewing quality of brightness,contrast, and colorfulness compared to the input image; wherein the atleast three-dimensional look-up table further comprises processing theinput image data to include chromatic adaptation of the human visualsystem to a specified white point that increases the brightness of theimage rendering unit.
 125. A computer implemented method of producing acolor image, the method comprising: a) providing input image data to thecomputer; b) using an at least three dimensional lookup table of valuesof input colors and output colors in the computer to convert input imagecolor data to output image color data, wherein the at leastthree-dimensional look-up table is based upon a model of human visualsystem perceptual adaptation, and is used to determine the output colorsin the at least three dimensional lookup table; and c) communicating theoutput image color data from the computer to an image rendering unit anddisplaying the color image on the image rendering unit; wherein thecolor image is perceived to have at least one of improved viewingquality of brightness, contrast, and colorfulness compared to the inputimage, and wherein input image data used to produce the image containsmemory colors and non-memory colors, and the method comprisesidentifying the memory colors in the input image data to besubstantially maintained, characterizing the memory colors andnon-memory colors with respect to their chromaticities, and producing animage with substantially maintained memory colors using the imagerendering unit.
 126. The method of claim 125, further comprisingpreserving memory colors of the image.
 127. The method of claim 125,further comprising performing empirical visual studies to determine thepreference of colorfulness, contrast, or brightness on the ethnicitiesof the human observers, and defining the perceived quality of the imagefor each nationality of human observers.
 128. The method of claim 127,further comprising adjusting the colorfulness, contrast, or brightnessof the image based upon one of the ethnicities of the human observers.129. The method of claim 125, wherein the at least three-dimensionallook-up table is used to adjust the colorfulness, contrast, orbrightness of the image to match the enhanced appearance of analog filmsystems or digital systems designed for cinemas.
 130. The method ofclaim 125, further comprising adjusting the colorfulness, contrast, orbrightness of the image to produce a chosen artistic perception in theimage.
 131. The method of claim 125, wherein the image rendering unit isof an expanded color gamut greater than the color gamut of input imagedata used to produce the image, and wherein the output colors to theimage rendering unit utilize the expanded color gamut.
 132. The methodof claim 125, wherein the image rendering unit is of a reduced colorgamut smaller than the color gamut of input image data used to producethe image and wherein the output colors to the image rendering unitutilize the reduced color gamut.
 133. The method of claim 125, whereinperceived colorfulness, brightness, and contrast of the non-memorycolors are changed differently than perceived colorfulness, brightness,and contrast of the memory colors.
 134. The method of claim 125, whereinperceived colorfulness, brightness, and contrast of the non-memorycolors are increased more than perceived colorfulness, brightness, andcontrast of the memory colors.
 135. The method of claim 125, wherein themethod includes generating the at least three-dimensional look-up tableincluding computing enhanced lightness, chroma, and hue for the memorycolors using a non-linear enhancement function.
 136. The method of claim125, further comprising generating more than one at leastthree-dimensional look-up table for the color transformation of thenon-memory colors and the memory colors.
 137. The method of claim 125,further comprising generating more than one at least three-dimensionallook-up table for the color transformation of the non-memory colors andthe memory colors, wherein each of the at least three dimensionallook-up tables is optimized for a different viewing environment of theimage rendering unit.
 138. The method of claim 137, further comprisingselecting one of the at least three-dimensional look-up tables forloading into an image color rendering controller based upon the viewingenvironment of the image rendering unit.
 139. The method of claim 138,further comprising providing a sensor for measuring the ambient light inthe viewing environment.
 140. The method of claim 125, wherein inputimage data used to produce the image is of a first color standard, andthe method further comprises converting the input image data of thefirst input color standard into an input color specification forinputting into the at least three-dimensional look-up table.
 141. Themethod of claim 125, wherein the at least three-dimensional look-uptable includes values of at least three input colors and values ofoutput colors.
 142. The method of claim 125, wherein the at leastthree-dimensional look-up table includes values of input colors andvalues of at least three output colors.
 143. The method of claim 142,wherein the at least three output colors are any combination of primarycolors as independent light sources or secondary colors defined ascombinations of primary colors.
 144. The method of claim 125, whereinthe at least three dimensional look-up table is losslessly compressed toreduce storage use in a memory of the image color rendering controller.145. The method of claim 125, further comprising calibrating the imagerendering unit by measuring the color response of the image renderingunit, and then modifying output image data by one of additionalprocessing after the at least three-dimensional look-up-table orincluding the required calibration in the at least three-dimensionallook-up-table.
 146. The method of claim 125, wherein an image colorrendering controller is provided within the image rendering unit. 147.The method of claim 125, wherein an imaging color rendering controlleris provided external to the image rendering unit.
 148. The method ofclaim 125, wherein an auxiliary imaging device controller is incommunication with an image color rendering controller and the imagerendering unit.
 149. The method of claim 125, wherein an image colorrendering controller is in communication with the image rendering unitselected from a projector, a television, a computer display, and a gamedisplay, the image rendering unit using DMD, plasma, liquid crystal,liquid crystal-on-silicon modulation, or direct modulation of the lightsource, and using LED, OLED, laser, or lamp light sources.
 150. Themethod of claim 125, wherein an image color rendering controller is incommunication with at least one of a cable TV set-top box, a video gameconsole, a personal computer, a computer graphics card, a DVD player, aBlu-ray player, a broadcast station, an antenna, a satellite, abroadcast receiver and processor, and a digital cinema.
 151. The methodof claim 125, wherein the image rendering unit includes an algorithm forcolor modification, and wherein the at least three-dimensional look-uptable further comprises processing the input image data to compensatefor the color modification performed by the image rendering unit. 152.The method of claim 151, wherein the image rendering unit includes analgorithm for creating secondary colors from primary colors, and the atleast three-dimensional look-up table further comprises compensating forthe color modification performed by the addition of the secondary colorsin the image rendering unit.
 153. The method of claim 151, wherein theat least three-dimensional look-up table is provided comprisingprocessing the input image data to increase perceived color, brightness,and contrast to compensate for the reduction in perceived color,brightness, and contrast caused by the algorithm for color modificationin the image rendering unit.
 154. The method of claim 125, wherein theat least three-dimensional look-up table contains a transformation froma suboptimal viewing environment to an improved viewing environmentincluding the visual adaptation of the human visual system, wherein theimage rendering unit is located in the suboptimal viewing environment,and wherein the color image in the image rendering unit is perceived toappear as it would in the improved viewing environment.
 155. The methodof claim 125, wherein the at least three-dimensional look-up tableincludes the definition of secondary colors, and contains improvedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of the secondarycolors by the image rendering unit.
 156. The method of claim 125,wherein the color image is a 3D color image comprised of two 2D stereoimages provided simultaneously.
 157. A computer implemented method ofproducing a color image, the method comprising: a) providing input imagedata to the computer; b) using an at least three dimensional lookuptable of values of input colors and output colors in the computer toconvert input image color data to output image color data, wherein theat least three-dimensional look-up table is based upon a model of humanvisual system perceptual adaptation, and is used to determine the outputcolors in the at least three dimensional lookup table; and c)communicating the output image color data from the computer to an imagerendering unit and displaying the color image on the image renderingunit; wherein the color image is perceived to have at least one ofimproved viewing quality of brightness, contrast, and colorfulnesscompared to the input image, and wherein the at least three-dimensionallook-up table further comprises processing the input image data toinclude chromatic adaptation of the human visual system to a specifiedwhite point that increases the brightness of the image rendering unit.158. A device for producing a color image, the device comprising acomputer comprising a central processing unit and a memory incommunication through a system bus, wherein the memory contains a set ofat least three dimensional lookup table of values of input colors andoutput colors defined using a model of human visual system perceptualadaptation, wherein the values in the lookup tables convert input imagecolor data to output image color data while maintaining memory colors inthe color image, in an image rendering unit that is connectable to thedevice, and wherein each one of the set of at least three dimensionallookup tables is optimized for a different viewing environment of theimage rendering unit.
 159. The device of claim 158, further comprisingthe image rendering unit in communication with the computer, the imagerendering unit selected from a projector, a television, a computerdisplay, and a game display, the image rendering unit using DMD, plasma,liquid crystal, liquid crystal-on-silicon modulation, or directmodulation of the light source, and using LED, OLED, laser, or lamplight sources.
 160. The device of claim 159, further comprising anauxiliary imaging device including at least one of a cable TV set-topbox, a video game console, a personal computer, a computer graphicscard, a DVD player, and a Blu-ray player, a broadcast station, anantenna, a satellite, a broadcast receiver and processor, and a digitalcinema.
 161. The device of claim 160, further comprising one of a liquidcrystal display, a plasma display, and a DMD projector in communicationwith the auxiliary device.
 162. The device of claim 158, furthercomprising a communication link to a source of input image data. 163.The device of claim 158, wherein the algorithm to produce the at leastthree dimensional lookup table is contained in the memory.
 164. Thedevice of claim 158, wherein the at least three-dimensional look-uptable includes the definition of secondary colors, and contains improvedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of the secondarycolors by the image rendering unit.
 165. The device of claim 158,wherein the at least three-dimensional look-up table contains atransformation from a suboptimal viewing environment to an optimalviewing environment including the visual and chromatic adaptation of thehuman visual system, wherein the image rendering unit is located in thesuboptimal viewing environment, and wherein an output image in the imagerendering unit is perceived to appear as it would in the improvedviewing environment.
 166. The device of claim 158, further comprising asensor for measuring the ambient light in the viewing environment. 167.The device of claim 158, wherein the color image is a 3D color imagecomprised of two 2D stereo images provided simultaneously.
 168. A devicefor producing a color image, the device comprising a computer comprisinga central processing unit and a memory in communication through a systembus, wherein the memory contains a set of at least three dimensionallookup tables of values of input colors and output colors defined usinga model of human visual system perceptual adaptation, wherein the valuesin the lookup table convert a first color gamut of an input image dataset to encompass a second different color gamut of an image renderingunit that is connectable to the device, and wherein memory colors aremaintained in the converting the first color gamut, and wherein each oneof the set of at least three dimensional lookup tables is optimized fora different viewing environment of the image rendering unit.
 169. Thedevice of claim 168, wherein the color gamut of the image rendering unitis larger than the first color gamut.
 170. The device of claim 168,wherein the color gamut of the image rendering unit is smaller than thefirst color gamut.
 171. The device of claim 168, further comprising theimage rendering unit in communication with the computer, the imagerendering unit selected from a projector, a television, a computerdisplay, and a game display, the image rendering unit using DMD, plasma,liquid crystal, liquid crystal-on-silicon modulation, or directmodulation of the light source, and using LED, OLED, laser, or lamplight sources.
 172. The device of claim 171, further comprising anauxiliary imaging device including at least one of a cable TV set-topbox, a video game console, a personal computer, a computer graphicscard, a DVD player, and a Blu-ray player, a broadcast station, anantenna, a satellite, a broadcast receiver and processor, and a digitalcinema.
 173. The device of claim 172, further comprising one of a liquidcrystal display, a plasma display, and a DMD projector in communicationwith the auxiliary device.
 174. The device of claim 168, furthercomprising a communication link to a source of input image data. 175.The device of claim 168, wherein the algorithm to produce the at leastthree dimensional lookup table is contained in the memory.
 176. Thedevice of claim 168, wherein the at least three-dimensional look-uptable includes the definition of secondary colors, and contains improvedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of the secondarycolors by the image rendering unit.
 177. The device of claim 168,wherein the at least three-dimensional look-up table contains atransformation from a suboptimal viewing environment to an improvedviewing environment including the visual and chromatic adaptation of thehuman visual system, wherein the image rendering unit is located in thesuboptimal viewing environment, and wherein an output image in the imagerendering unit is perceived to appear as it would in the improvedviewing environment.
 178. The device of claim 168, further comprising asensor for measuring the ambient light in the viewing environment. 179.The device of claim 168, wherein the color image is a 3D color imagecomprised of two 2D stereo images provided simultaneously.
 180. A devicefor producing a color image, the device comprising a computer comprisinga central processing unit and a memory in communication through a systembus, wherein the memory contains a set of at least three dimensionallookup tables containing a transformation from a suboptimal viewingenvironment to an improved viewing environment including the visual andchromatic adaptation of the human visual system defined using a model ofhuman visual system perceptual adaptation, and wherein memory colors aremaintained in the color image, and wherein each one of the set of atleast three dimensional lookup tables is optimized for a differentviewing environment of the image rendering unit.
 181. The device ofclaim 180, further comprising an image rendering unit in communicationwith the computer, the image rendering unit selected from a projector, atelevision, a computer display, and a game display, the image renderingunit using DMD, plasma, liquid crystal, liquid crystal-on-siliconmodulation, or direct modulation of the light source, and using LED,OLED, laser, or lamp light sources.
 182. The device of claim 181,further comprising an auxiliary imaging device including at least one ofa cable TV set-top box, a video game console, a personal computer, acomputer graphics card, a DVD player, and a Blu-ray player, a broadcaststation, an antenna, a satellite, a broadcast receiver and processor,and a digital cinema.
 183. The device of claim 182, further comprisingone of a liquid crystal display, a plasma display, and a DMD projectorin communication with the auxiliary device.
 184. The device of claim180, further comprising a communication link to a source of input imagedata.
 185. The device of claim 180, wherein the algorithm to produce theat least three dimensional lookup table is contained in the memory. 186.The device of claim 180, wherein the at least three-dimensional look-uptable includes the definition of secondary colors, and contains improvedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to addition of the secondarycolors by the image rendering unit.
 187. The device of claim 180,further comprising a sensor for measuring the ambient light in theviewing environment.
 188. The device of claim 180, wherein the colorimage is a 3D color image comprised of two 2D stereo images providedsimultaneously.
 189. A device for producing a color image, the devicecomprising a computer comprising a central processing unit and a memoryin communication through a system bus, wherein the memory contains a setof at least three dimensional lookup tables defined using a model ofhuman visual system perceptual adaptation and containing the definitionof secondary colors, and enhanced lightness, chroma, and hues toincrease perceived colorfulness, contrast, or brightness to compensatefor the loss in perceived colorfulness, contrast, or brightness due toaddition of secondary colors by an image rendering unit that isconnectable to the device, wherein memory colors are maintained in thecolor image, and wherein each one of the set of at least threedimensional lookup tables is optimized for a different viewingenvironment of the image rendering unit.
 190. The device of claim 189,further comprising the image rendering unit in communication with thecomputer, the image rendering unit selected from a projector, atelevision, a computer display, and a game display, the image renderingunit using DMD, plasma, liquid crystal, liquid crystal-on-siliconmodulation, or direct modulation of the light source, and using LED,OLED, laser, or lamp light sources.
 191. The device of claim 190,further comprising an auxiliary imaging device including at least one ofa cable TV set-top box, a video game console, a personal computer, acomputer graphics card, a DVD player, and a Blu-ray player, a broadcaststation, an antenna, a satellite, a broadcast receiver and processor,and a digital cinema.
 192. The device of claim 191, further comprisingone of a liquid crystal display, a plasma display, and a DMD projectorin communication with the auxiliary device.
 193. The device of claim189, further comprising a communication link to a source of input imagedata.
 194. The device of claim 189, wherein the algorithm to produce theat least three dimensional lookup table is contained in the memory. 195.The device of claim 189, wherein the at least three-dimensional look-uptable contains a transformation from a suboptimal viewing environment toan improved viewing environment including the visual and chromaticadaptation of the human visual system, wherein the image rendering unitis located in the suboptimal viewing environment, and wherein an outputimage in the image rendering unit is perceived to appear as it would inthe improved viewing environment.
 196. The device of claim 189, furthercomprising a sensor for measuring the ambient light in the viewingenvironment.
 197. The device of claim 189, wherein the color image is a3D color image comprised of two 2D stereo images providedsimultaneously.
 198. A device for producing a color image perceived byhuman observers observing the image on an image rendering unit, thedevice comprising a computer comprising a central processing unit and amemory in communication through a system bus, wherein the memorycontains a model of human visual system perceptual adaptation to enhancethe perceived colorfulness, contrast, or brightness of the image,wherein memory colors are maintained in the color image, and wherein thememory contains a set of at least three dimensional lookup tables, eachone of the set containing values of input colors and output colors, andeach one of the set optimized for a different viewing environment of theimage rendering unit.
 199. The device of claim 198, further comprisingthe image rendering unit in communication with the computer, the imagerendering unit selected from a projector, a television, a computerdisplay, and a game display, the image rendering unit using DMD, plasma,liquid crystal, liquid crystal-on-silicon modulation, or directmodulation of the light source, and using LED, OLED, laser, or lamplight sources.
 200. The device of claim 199, further comprising anauxiliary imaging device including at least one of a cable TV set-topbox, a video game console, a personal computer, a computer graphicscard, a DVD player, and a Blu-ray player, a broadcast station, anantenna, a satellite, a broadcast receiver and processor, and a digitalcinema.
 201. The device of claim 200, further comprising one of a liquidcrystal display, a plasma display, and a DMD projector in communicationwith the auxiliary device.
 202. The device of claim 198, furthercomprising a communication link to a source of input image data. 203.The device of claim 198, wherein the algorithm to produce the at leastthree dimensional lookup table is contained in the memory.
 204. Thedevice of claim 198, wherein the at least three-dimensional look-uptable contains a transformation from a suboptimal viewing environment toan improved viewing environment including the visual and chromaticadaptation of the human visual system, wherein the image rendering unitis located in the suboptimal viewing environment, and wherein an outputimage in the image rendering unit is perceived to appear as it would inthe improved viewing environment.
 205. The device of claim 198, furthercomprising a sensor for measuring the ambient light in the viewingenvironment.
 206. The device of claim 198, further comprising the imagerendering unit in communication with the computer, wherein the values inthe lookup table convert a first color gamut of an input image data setto encompass a second expanded color gamut of the image rendering unit.207. The device of claim 198, further comprising the image renderingunit in communication with the computer, wherein the values in thelookup table convert a first color gamut of an input image data set toencompass a second reduced color gamut of the image rendering unit. 208.The device of claim 198, further comprising the image rendering unit incommunication with the computer, wherein the at least three dimensionallookup table contains the definition of secondary colors, and improvedlightness, chroma, and hues to increase perceived colorfulness,contrast, or brightness to compensate for the loss in perceivedcolorfulness, contrast, or brightness due to the addition of secondarycolors by the image rendering unit.
 209. The device of claim 198,wherein the color image is a 3D color image comprised of two 2D stereoimages provided simultaneously.